This is a weird story:
Hernandez was able to evade capture for so long because he used Tails, a version of Linux designed for users at high risk of surveillance and which routes all inbound and outbound connections through the open-source Tor network to anonymize it. According to Vice, the FBI had tried to hack into Hernandez’s computer but failed, as the approach they used “was not tailored for Tails.” Hernandez then proceeded to mock the FBI in subsequent messages, two Facebook employees told Vice.
Facebook had tasked a dedicated employee to unmasking Hernandez, developed an automated system to flag recently created accounts that messaged minors, and made catching Hernandez a priority for its security teams, according to Vice. They also paid a third party contractor “six figures” to help develop a zero-day exploit in Tails: a bug in its video player that enabled them to retrieve the real I.P. address of a person viewing a clip. Three sources told Vice that an intermediary passed the tool onto the FBI, who then obtained a search warrant to have one of the victims send a modified video file to Hernandez (a tactic the agency has used before).
Facebook also never notified the Tails team of the flaw—breaking with a long industry tradition of disclosure in which the relevant developers are notified of vulnerabilities in advance of them becoming public so they have a chance at implementing a fix. Sources told Vice that since an upcoming Tails update was slated to strip the vulnerable code, Facebook didn’t bother to do so, though the social media company had no reason to believe Tails developers had ever discovered the bug.
“The only acceptable outcome to us was Buster Hernandez facing accountability for his abuse of young girls,” a Facebook spokesperson told Vice. “This was a unique case, because he was using such sophisticated methods to hide his identity, that we took the extraordinary steps of working with security experts to help the FBI bring him to justice.”
I agree with that last paragraph. I’m fine with the FBI using vulnerabilities: lawful hacking, it’s called. I’m less okay with Facebook paying for a Tails exploit, giving it to the FBI, and then keeping its existence secret.
EDITED TO ADD: This post has been translated into Portuguese.