Reverse Location Search Warrants

The police are increasingly getting search warrants for information about all cell phones in a certain location at a certain time:

Police departments across the country have been knocking at Google's door for at least the last two years with warrants to tap into the company's extensive stores of cellphone location data. Known as "reverse location search warrants," these legal mandates allow law enforcement to sweep up the coordinates and movements of every cellphone in a broad area. The police can then check to see if any of the phones came close to the crime scene. In doing so, however, the police can end up not only fishing for a suspect, but also gathering the location data of potentially hundreds (or thousands) of innocent people. There have only been anecdotal reports of reverse location searches, so it's unclear how widespread the practice is, but privacy advocates worry that Google's data will eventually allow more and more departments to conduct indiscriminate searches.

Of course, it's not just Google who can provide this information.

I am also reminded of a Canadian surveillance program disclosed by Snowden.

I spend a lot of time talking about this sort of thing in Data and Goliath. Once you have everyone under surveillance all the time, many things are possible.

EDITED TO ADD (3/13): Here' the portal law enforcement uses to make its requests.

Posted on February 21, 2019 at 6:33 AM • 35 Comments

Comments

nwcsFebruary 21, 2019 7:11 AM

Kind of wondering how this will play out in courts. The Fourth Amendment prohibits general warrants which do not describe the persons being searched. This is mentioned by the EFF here:

Jennifer Lynch, senior staff attorney at digital and human rights body the Electronic Frontier Foundation, said that the order in Hernico could’ve swept up the locations of thousands of innocent people. “Requests like this act as ‘general warrants’ and may violate the Fourth Amendment because they are not tied to a specific device,” Lynch added. The Fourth Amendment provides Americans with a right to protect themselves from unreasonable searches.

dimirFebruary 21, 2019 8:22 AM

There has been an interesting talk about the situation in Germany at the last Chaos Communication Congress. The speakers were able to get some approximate numbers from authorities about the frequency of such warrants through freedom of information requests. The video is available here:

https://media.ccc.de/v/35c3-9972-funkzellenabfrage_die_alltagliche_rasterfahndung_unserer_handydaten#t=0

(The talk is in German but the Englisch audio track can be selected in the lower right corner of the video)

parabarbarianFebruary 21, 2019 9:09 AM

I doubt this is any more a Fourth Amendment violation than using video in an investigation. A video camera captures un-involved people all the time and very few people doubt it's legitimate to use in criminal investigations and a subsequent trials.

65535February 21, 2019 9:21 AM

I do not like Giggle or Alphabet or their other subsidies.

Giggle is turning out to be the largest corporate intelligence agency in the USA – or the world. The huge corperate power of Giggle is eveident:

[Wikipedia]

“Google Street View privacy concerns… Privacy advocates have objected to the Google Street View feature, pointing to photographs that show people leaving strip clubs, protesters at an abortion clinic, sunbathers in bikinis, cottagers at public parks, people picking up prostitutes and people engaging in activities visible from public property which they do not wish to be photographed and have published online... Google maintains ...the photos were taken from public property… this does not take into account that the Street View cameras take pictures from an elevated position, enabling them to look over hedges and walls designed to prevent some areas from being open to public view....Privacy advocates have objected to the Google Street View feature, pointing to photographs that show people leaving strip clubs, protesters at an abortion clinic, sunbathers in bikinis, cottagers at public parks, people picking up prostitutes and people engaging in activities visible from public property which they do not wish to be photographed and have published online…Google maintains that the photos were taken from public property. However, this does not take into account that the Street View cameras take pictures from an elevated position, enabling them to look over hedges and walls designed to prevent some areas from being open to public view.”-Wikipedia

https://en.wikipedia.org/wiki/Google_Street_View_privacy_concerns

“Google Street View … Cameras: Street View imagery has come from several generations of camera systems from Immersive Media [1], Point Grey Research (now FLIR Systems) [2] and developed in-house…The cameras contain no mechanical parts, including the shutter, instead using CMOS sensors and an electronic rolling shutter. Widely deployed versions… R2: the earliest after Immersive Media, photos were captured with a ring of eight 11-megapixel CCD sensors with commercial photographic wide-angle lenses, cameras with the same specs as those used for the Google Books project... Ladybug2 cameras (resolution 1024 x 768 pixels) by Point Grey Research…R5: uses … ring of eight 5-megapixel CMOS cameras by Elphel[39][40] with custom low-flare lenses, plus a camera with fisheye lens on top to capture upper levels of buildings. …. R7: is the first completely in-house built camera.. uses 15 of the same sensors and lenses as R5, but no fish-eye... 2017 uses 8 20MP cameras. Includes two facing left …right to read street signs and business names...” -Wikipedia…”

[And]

“Positioning: recorded photographs must be associated with accurate positioning. This is done via a Global Positioning System, wheel speed sensor, and inertial navigation sensor data… Laser range scanners from Sick AG for the measuring of up to 50 meters 180° in the front of the vehicle. These are used for recording the actual dimensions of the space being photographed…LIDAR scanners from Velodyne were added in the 2017 update. Mounted at 45° to capture 3D depth information, and used for additional positional information….Vehicles: data recording equipment is usually mounted on the roof of a car. A Trike (tricycle) was developed to record pedestrian routes including Stonehenge, and other UNESCO World Heritage sites. In 2010 a snowmobile-based system captured the 2010 Winter Olympics sites.[37] Trolleys have been used to shoot the insides of museums, and in Venice the narrow roads were photographed with backpack-mounted cameras, and canals were photographed from boats... A portable back-pack Google Trekker is used …outdoor terrain. For instance, the six main paths up Snowdon were mapped by the Google Trekker in 2015”- Wikipedia

https://en.wikipedia.org/wiki/Google_Street_View

This is like a leg trap on a huge scale. Out of control. All very troubling.

TimHFebruary 21, 2019 9:31 AM

@parabarbarian: I can think of two differences. One, walking in public doesn't have an expectation of privacy, where identifying people via the cell phone location does. Secondly, you can wear a hoodie and dark glasses in public, disguise your gait etc, but that isn't possible with a cell phone.

Lastly, carrying a cell phone is essentially mandatory for many people now; by job, for social engagements, for managing kids etc. So the argument is increasingly unreasonable that a cell phone user has to accept pervasive surveillance as part of the contract.

entangledsunlightFebruary 21, 2019 9:58 AM

Hi parabarbarian,

I might point out that in years past every one of the people in the video would be unknown to investigators w/o serious efforts to uncover their identities. This "serious efforts" would be economic incentive to stick to the man actually robbing the bank on video.

Now, technology can -without any significant cost- identify each and every individual in a "reverse location" search. Even the video (with new technology like face recog - might identify most of them. Very significantly different can of pearls, dontcha think?

Petre Peter February 21, 2019 10:35 AM

Living from inside my cell i realized that the plan was to be in a cell plan so that my cell can be searched at cellular levels. "What plan are you on?"

AdrianFebruary 21, 2019 11:37 AM

I saw a talk a while back from a police detective who solved a widely-publicized murder case in my city.

When speaking about methods they use in general, he said they would often go to the cell network operators for "tower dumps," which is a list of every cell phone that pinged a given antenna tower during a certain period of time. He explained that they're often used as a tool to find potential witnesses, saying that they usually had a suspect but were trying to build a case for the prosecutor.

My understanding is that tower dumps were cheap and easy to get, but we've since had some court rulings that now require the police to get a warrant for a tower dump. I wonder how much that's curtailed their use or if the courts just routinely grant the warrants.

CallMeLateforSupperFebruary 21, 2019 11:45 AM

A thumbs-up to the article's author for careful wording {EMPHASIS mine}:
"[...] allow law enforcement to sweep up the coordinates and movements of every CELLPHONE in a broad area."

LE locates and/or tracks a CELLPHONE and uses the data to prove geolocation or movement of the OWNER of that cellphone.

VRKFebruary 21, 2019 11:54 AM

TimH

"walking in public doesn't have an expectation of privacy"

Dang. This may be the new norm, but really... a public place is also "essentially mandatory for many people now...". I have a big problem with five cameras on one city bus etc. If people are THAT insecure, how is video footage going to help during YOUR rape, etc. Follow-up is being sold as CURRENT security even tho it does NOTHING for your current perils when a gang of monsters from the local "militant order" / vigilante group finally pushes someone over the edge, for example. It's an endless supply of risk vectors, morphing continuously.

The ONLY form of protection is hiding in a faraday cage the rest of your life, and getting someone to slip porridge under the door. Cops are ALWAYS ten minits, ten hours, or TEN YEARS too late: They physically CANT help you no matter how many cell numbers they accumulate.

Your cellphone IS presently another accursed pipeline for freaks from EVERY side.

Befriend a farmer. Get off the grid. Think more about AFTER yer dead.

CallMeLateForSupperFebruary 21, 2019 12:30 PM

I'd like to see those Google Street View pix that allegedly violate individuals' right to privacy.

In ~10 years of browsing Street View I have noted that Google's "advanced technology" blurred not only vehicle license plates and the faces of persons but also decidedly dead objects such as street signs and navigation aid signs on four-lane highways,

Yet, even as faces and vehicle tags are nearly always obscured, Google's "advanced technology" is not perfect. In a car park in a borough of Drammen, Norway, I spotted a lone UNblurred licence plate among many parked cars, and an UNblurred couple bobbing in a tiny back yard pool.

JG4February 21, 2019 12:31 PM


I didn't see "endpoint security" mentioned in here, but it at least sheds a little bit of light for the average person.

https://www.wired.com/2017/02/famed-hacker-kevin-mitnick-shows-go-invisible-online/

It also didn't mention the extra scrutiny that could come from mentioning TOR in an email. Or in a comment.

I was pleased to see that the US Supreme Court finally ruled on seizures of property as being fines subject to the 14th Amendment. I'd like to see the equal protection clause used aggressively in cases like Volkswagen. And Scamazon.

CallMeLateForSupperFebruary 21, 2019 12:41 PM

@VRK
"Cops ... CANT help you no matter how many cell numbers they accumulate."

Mostly true. Consider, though, that they are looking to close existing cases, not to thwart imminent dangers.

1&1~=UmmFebruary 21, 2019 12:42 PM

"Once you have everyone under surveillance all the time, many things are possible."

And with the idea of "Innocent until proved guilty" now removed from much of more recent legislation and court behaviour... where the burden of proof now falls not on the prosecution but the defendant, but with,

1, The defendant not able to get access to records because they are "third party business" to show they are innocent.

2, Or that there is significant doubt in the evidence presented by the prosecution[1].

3, Or that the evidence presented by the prosecution is false (claim / imply GPS accuracy, when position is derived by some other method like signal strength at only one cell mast[1]).

In nations with 'plea barging' where the defendent virtually never gets to see let alone have independently assessed "raw evidence", just what the prosecutor scares them into believing that they have as evidence. Is it surprising there will be innocent people going to jail?

[1] Location data is not what you might think it is look up triangulation "cocked hat" errors and biagulation ambiguity. It's even worse when all it is based on is "signal strength at the mast of a single cell site. Industry insiders know that on signal strength two different cell sites could have you several Km appart especially in certain types of terrain.

TimHFebruary 21, 2019 1:23 PM

@CallMeLateForSupper: When you and I browse Street View we see on-the-fly blurring. I bet 3rd parties can buy the images without it. So privacy implication, not practice.

John CampbellFebruary 21, 2019 2:36 PM

Y'know, someone will decide this is a means to scoop up WITNESSES along with suspects if only to justify why such a broad drag net is being deployed.

Mind you, this is still overreach and proof that our "phones" are little more than a surveillance robot we willingly carry.

David RudlingFebruary 21, 2019 5:11 PM

@Warren
If you again read Bruce Schneier's post above you will see
"Of course, it's not just Google who can provide this information."
I don't dispute the thrust of what you say but limiting it to the one company quoted as an example is a little unfair - it is an industry wide issue.

Rach ElFebruary 21, 2019 9:31 PM

Thanks everyone

The general theme is people fearing this information could be used beyond its brief, against the innocent

multiple components to this situation

i wonder if it can be compounded by intentional use of sting-rays

and if it would fly outside of US of A

I suspect it would not hold up too well to a strong defence in court - where it counts

And the erroneous, speculative geo-nature of th is data


i lived in a suburb where a famous abuduction case had occurred years before I moved there. It was to achieve national attention. my neighbour said the police assessed every single text message sent in the whole area before and during the day of the event in hope of finding suspects. She knew this because her son had sent some text message about taking car somewhere (to the mechanic or something) and the police actually paid him a personal visit to have him explain what he meant.


- CallMeLateForSupper

'LE locates and/or tracks a CELLPHONE and uses the data to prove geolocation or movement of the OWNER of that cellphone.'

i suspect you are making an astute observation here. I just cannot be sure of what it is. Would you mind extrapolating?

Rach ElFebruary 21, 2019 9:35 PM

CallMeLateForSupper

RE: previous comment

Are you noting the discrepancy between CELLPHONE and OWNER and spurious associaton thereof? Prima facie (on the face of it) they are synonymous unless exceptional use-case can be proven. Love, Rachel


Ismar February 22, 2019 3:47 AM

I would like to turn this on its head and suggest a scenario where people can be framed by falsifying their phone location at a time and place of a crime.
This should not be impossible nor even too hard given the current stage of phone / computer technology.

meFebruary 22, 2019 4:39 AM

@parabarbarian

> I doubt this is any more a Fourth Amendment violation than using video in an investigation. A video camera captures un-involved people all the time and very few people doubt it's legitimate to use in criminal investigations and a subsequent trials.


I'm for privacy all the time but i see in location a valuable tool for law enforcment, exactly like security camera.

BUT! it must not be abused, for me it's fine if they gather video and location data of people near the crime scene.
for me is NOT OK if they gather video/location data all the time for example: automated license plate readers in usa (i'm in italy)

i know that in one case where there were multiple theft at different stores google gave only location of who was near both the store in that moment instead of giving location of all the people near the two stores.

anyway i can't understand why privacy people (i consider myself a "privacy person" whatever it means) are mad about this because is used to catch criminals and are not mad about google collecting data about anyone all the time for commercial purposes!
this is the real problem! and no, people never gave google the consent, they have been tricked into giving it at best.

Givon ZirkindFebruary 22, 2019 6:50 AM

The rub is, that unfortunately, if you are looking for terrorists or bank robbers, whatever, you want to find with whom they are associating. You are studying their human network. Tracking could be much more involved and require a longer period of time. The Walker spy case is one good example.

The investigative turning point in the Walker spy case was when the FBI agent, typed in the data from all the airline manifests with the suspected 2 spies on them and; voila! You could see their periodic or timely meetings in Mexico City.

The question now becomes, how often do things like this happen? How often do such investigations occur? Is the tradeoff worth it?

I read Data & Goliath. Mr. Scheier posits a good argument that such sweeping data collection is not necessary and; is not done in other examples of similar investigations with the bad guys still being caught. Using terrorism as fear mongering for control, is not something we should pander to.

CallMeLateForSupperFebruary 22, 2019 10:48 AM

@Rach El
"Are you noting the discrepancy between CELLPHONE and OWNER and spurious associaton thereof?"

I think so ,,, the "spurious association" part. I am saying that data showing that a particular phone squawked from a particular geoloc. at a particular time is not necessarily proof that the phone's owner was at said location at said time. Phones are not physically and irreversibly attached to their owners, so they *can* be separated in space.

"Prima facie (on the face of it) they are synonymous unless exceptional use-case can be proven."

I fail to see that "exceptional use case" fits in here so I'll just ignore that. If, by synonymous, you mean that LE *assumes* that a phone and its owner are always co-located, then I would agree; they seem to assume that. I would also hasten to point out that the assumption is flawed; it is not always true.

vas pupFebruary 22, 2019 11:07 AM

@Rach El • February 21, 2019 9:35 PM
CELL PHONE > OWNER
CAR > OWNER
GUN > OWNER
The burden of proof remains on accuser: prosecutor/LEO.
Cell phone, car, gun - you name it are just preliminary information, because they are not 'part' of the suspect. Fingerprints, DNA are 'part' of the suspect. You got what I mean.

@all: regarding privacy, mass data collection by LEAs in open space with or without court order. That was/is/will be always to some degree in any country (degree depends on actual set of threats: criminals, terrorists, rebels, foreign agents, etc. and available technology).
My concern is about usage of such collected information, not collection itself. If it is used for criminal intelligence ONLY, stay with LEAs, not disclosed to ANY third party (press, media, business you name it) and used only to developed leads for investigation, that is fine with me, BUT when they try to use it DIRECTLY for prosecution, leaking such information to the media, your employer, landlord, friends (in particular with gag order), that is modern version of '1984' on steroids, and I strongly object such practice.
Time and again, please see difference between collection information as part of criminal intelligence and obtaining evidence of crime accepted by the court.

1&1~=UmmFebruary 22, 2019 1:20 PM

@CallMeLateForSupper: Rach El:

"I am saying that data showing that a particular phone squawked from a particular geoloc. at a particular time is not necessarily proof that the phone's owner was at said location at said time."

You should also note it is not proof the phone was at the given location,

1, At that time.
2, Ever.

Until people realy get to understand that simple fact, then there will be injustice after injustice.

VRKFebruary 22, 2019 3:45 PM

@ Gang, @ vas pup forgive the morbid pessimism. I do try to focus constructively.

I've been watching this first hand for ten years; "collection itself" means every cell owner today is a lab rat.

And btw, isn't the continued shift to fiber indicative of something deeply amiss with cell tech? Yowza. They're going to do it again: you pay for it all to be installed, and then they yank it all out from under you and rewrite the rules for engagement.

Rev 13:17 "...they could not buy or sell unless they had the mark..."

(Get off the grid...)


Rach ElFebruary 22, 2019 4:26 PM

CallMeLateForSupper
VasPup
1&1~=Umm

Regarding CELLPHONE:OWNER correlation

good feedback. I too am suggesting that, in court - which is where it counts [whatever LE claims, only matters if it ends up in court] it would not be too difficult to have an adequate defence against such spurious allegations. Not least with a technical argument in support.
The difficulty is that it's like fingerprints and other questionable evidence. Unless you're a commentator on Schneier.Com, no one in the court room is going to know the technical facts [including LE] and so the magistrate will just roll with what the proseuction alleges 'triangulation shows, via this diagram we constructed, the suspect was at the scene'

CallMeLateForSupper


"I fail to see that "exceptional use case" fits in here so I'll just ignore that. If, by synonymous, you mean that LE *assumes* that a phone and its owner are always co-located, then I would agree; they seem to assume that. I would also hasten to point out that the assumption is flawed; it is not always true."

I meant, that, unless an exceptional situation can be demonstrated, 'on the face of it' a magistrate is going to say, yes, it is fair to assume a person and their phone are together most of the time. No, the phone was not abducted by aliens, no it wasn't borrowed by the plumber. People take their wallet, and their keys, and their phone with them everywhere. Especially if one has enough telco data, text message context etc to demonstrate it is the case most of the time.
Share your phone with your spouse 50% of the time? Prove it? Okay, great, you're halfway off the hook but we have a new suspect now

1&1~=UmmFebruary 23, 2019 6:22 AM

@Rach El:

"Share your phone with your spouse 50% of the time? Prove it? Okay, great, you're halfway off the hook but we have a new suspect now"

Quite a few years ago now a UK Newspaper editor tried running a little experiment with 'work phones'. Put simply they were used "from a pool" that is at the start of the day you handed in your 'yesterdays mobile' and got given your 'today mobile' and the editorial switchboard operator was given a list of who had each mobile phone so they could forward calls to the correct mobiles.

It went wrong for the editorial team not technically or because of the switchboard operators but because of the editorial team 'OpSec issues'.

However where an editorial team failed, ordinary workers do not have any great issues with Private Mobile Radio (PMR) vehicle and two way radio replacments. They do not regard the PMR equipment as 'personal' but 'company' so switching the PMR equipment for mobile phone equipment caused them little or no issues.

You also see this in a slightly diffetent way in the UK with some 'first responder' emergency services. Due to two political requirments they have been saddled with a compleatly hopeless TETRA system bassed on very out of date Motorola[1] system[2], which the 'troops on the ground' hate with a passion that would shock many. In the case of the London Metropolitan Police Force, those troops have come up with their own solutions bassed around mobile phones. Often you will see the officers with two or three mobile phones and as far as I'm aware having spoken to a number of them they don't have OpSec issues with the mobile phone systems they have set up by trial and error, but TETRA the list is both long and grevious.

The 273Kg (600lb) gorilla officials are avoiding talking about is 'What next?'. They know without a doubt TETRA can not cope with even a fraction of emergancy service traffic on an ordinary day, which is why the ad hoc mobile phone systems came into existance. The rise in traffic is only going to increase and funding decrease. But there are other emergancy plans to turn off mobile phones in an emergancy such as a major terrorist attack. Thus something is going to have to give if not fracture entirely, the only questions are 'When, Why and How?' with 'How?' already fairly well predicted.

[1] https://www.motorolasolutions.com/en_xu/communications/uk-public-safety/uk-tetra-solutions.html

[2] TETRA or Terestrial Trunked Radio is hopless for a number of reasons. Firstly it's a case of trying to squeeze a quart into a pint pot, the process producess a badly degraded result, which sellers of such systems try to avoid talking about. Secondly is the 'Designed by committee' to be an 'All things to all men' solution including high security. The result is a system that is fundamentaly much poorer in performance and so over complicated to configure, that nobody can work out how to set it up correctly, thus the 'lowest common denominator' rule applies and every one gets the worst of everything. Including no voice/data security, short battery life due to every unit opening up for every message from every area and consequently awful OpSec, worse than when it was plain voice FM two way radio. Oh and due to other reasons vastly increased amounts of traffic, such that it's 'bursting at the seams' in non emergancy situations due to lack of capacity (that the UK Treasury has sold off). What will happen in a genuine emergancy is yet to be found out, but longer term first responder emergancy personnel remember 7/7 from 2005 with dread.

Rach ElFebruary 23, 2019 2:54 PM


1&1~=Umm

I see you :-) I was a bit slow. But, I understand. Glad all is well, my anxiety is now alleviated

Rach ElFebruary 23, 2019 3:20 PM

Appreciate the detailed comments about TETRA. As a professional wildfire fighter I witnesed this first hand. our emergency services authority was hammered by a peak fire incident that wiped out lots of civiliation, with coronial inquests and hearings piling up and blame spread thin. One proposal quickly integrated was to upgrade the entire radio comms network for all agencies, which also included the volunteer brigades who do wilderness search and rescue, firefighting amongst other things.
Many, many millions later, voila TETRA. Now, we're not always the brightest tools in the shed but it must be said everyone had such a headache getting their heads around using them. The cost of a single handset was so, so high we were nervous about even using them - dropping them, getting them near a fire, near water - oh funny, that - fire...water..
I remember their size and weight, the EMF emissions so palpable we joked about toasting marshmallows. No one could adapt to having to wait a number of seconds for the trunk relay to kick in after depressing push to talk, so the beginning of Tx was always cut off. I remember all the hype around the features - this was before smart phones existed - yet we wondered why we'd ever need many of them.

I recall a training drill in my crew - prepare for burn over - where ones vehicle is about to be engulfed by a firefront.(1) There's a routine for nominating a post-incident rendevous, nominating who will be on comms and who on first aid, grabbing the fireblankets, closing all air-ingress points and huddling up on floor of vehicle under a fire blanket. And preparing to die.(2)

Someone in my crew called in the code red 'we are at this location, preparing for burn over' on the training comms channel. However the new TETRA handset reverted to the default official public emergency channel.
30 minutes later emergency vehicle turned up, shortly followed thereafter by the brass wanting to know what the familyblog was going on and whose head was going to roll, for reporting a code red burnover incident?

6 months later the extremly expensive TETRA was rolled up and sent home and the pre-peak fire incident comms - stated to be ineffective by the hearings - was returned to its former status. If you can appreciate just how difficult it would be to reverse the findings of the Hearing, AND reverse something as fundamental as the comms network. Just what sort of experiences must have been had across multiple first responder agencies for them to actually backtrack on the TETRA - really tells you something. Well that was a fun waste of time.
I'm interested the London Met have persisted as long as they have.

(1) One should never be in this situation. Cardinal rule is 'Work from the black' means, ones vehicle should always be on burnt ground. Mind you one is often without a vehicle, having been delivered by helicopter in dense environments. Facing fire on foot with a backpack is - interesting

(2) The chance of survival is basically zero.The drill is akin to school kids climbing under their desks in the case of the atomic bomb. One doesn't perish in the flames, though, as the imagination expects. Death is inhalation of 'superheated air' which apparently occurs in seconds and is relatively painless and merciful. The other extreme risk is all the PVC and related materials inside the vehicle. Highly, highly toxic environment when combined with fire.

1&1~=UmmFebruary 23, 2019 7:21 PM

@Rach El:

"As a professional wildfire fighter I witnesed this first hand."

I tip my hat towards you that is not a job for the feint hearted.

I did basic training for shipboard fire fighting and for Helo decks as well, for offshore work. Back then aluminium was still a major fire hazard and for obvious reasons it and GRP were all over the place. I thought back then that 'learning to walk on water' might have been the safer option.

I still have issues a third of a century later of having to explain to people why it comes to structural uses why both iron and aluminium are best cased in wood even if it's not much thicker than 3ply rather than GRP or PVC. Likewise why wooden cupboards are better than pressed metal when it comes to storing chemicals even oxidative ones. Oh that and explaining why PVC should never ever be used where fire is even a remote possibility (thus why plenum cables are oh so expensive).

One of my constant annoyances is those who sit on committees deciding with 20-20 hindsight who or what is to blaim without one iota of real knowledge of the problem domain. Apparently they are to be respected not so much for this apparent skill, but as they have sufficient traits of psychopaths to have rapidly climbed the political greasy pole over the bodies of god alone knows how many people.

Speaking of superheated air did you ever hear about the exploding Russians? Apparently due to an attempt to cut back drunken behaviour the price of alcohol was raised substantially, something that has been tried repeatedly with little success[1]. Because some Russians always start brewing and then distilling their own[2] 'samogon'. However unlike commercial spirits that are rarely more than 40% by volume (80% proof), this stuff having been atleast double distilled to get rid of fusil oils[3] in the process could get over 90% by volume. Thus at body temprature easily capable of evaperating sufficiently to cross the lower explosive limit in air. Thus in their throats and lungs these Russians had the equivalent of a fuel air explosive (FAE/FAX). So they would be sitting there playing cards and smoking and at some point one of them would light a cigarette and in the process draw in the excess alcohol burning in the air. Thus igniting their internal FAE in their lungs, there would be a small poping noise a suprised look and then falling dead from their chair.

@ALL:

For the increasing numbers of 'preppers' living of the land is not going to be sufficient to survive and thrive. You should be looking for 'trade good skills' growing potatoes is not difficult, barley for malting/mashing is a little harder but not much. Thus learning to make Samogan --moonshine vodka-- is a skill worth having. Likewise knowing how to make charcoal for filtering not just the vodka but to make potable water, basic medicine and gunpowder, abd getting forge temperatures hot enough for metal working. You can also use potato vodka in the same way you can gin to make preserved soft fruit liquors, which also preserves certain important vitamins. As for the methonal (wood alcohol) and fusel oils that come from both tailings of distilling these are usefull for making the likes of lacquers and other semi-industrial products including wood glues, waterproofing agents and lubricants. You also should know how to "get nitrates, phosphorus and sulfur from nature". As these will also help with making soaps, medicines, gunpowder and preserving meat for another useful trade good skill charcuterie.

[1] https://www.theguardian.com/world/2010/jun/21/russia-shock-ads-price-vodka

[2] https://www.instructables.com/id/Potato-Vodka/

[3] https://en.m.wikipedia.org/wiki/Fusel_alcohol

hiding outFebruary 23, 2019 11:07 PM

Another problem with such sweeps is that they collect data on people who are in the area, but inside private spaces - homes/apartments, private vehicles, etc.

vas pupFebruary 24, 2019 2:00 PM

@hiding out • February 23, 2019 11:07 PM
You do have good point. Such practice in absolutely unacceptable as violation of 4th Amendment.

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