Schneier on Security

Random Bag Searches in Subways

Last year, New York City implemented a program of random bag searches in the subways. It was a silly idea, and I wrote about it then. Recently the U.S. Court of Appeals for the 2nd Circuit upheld the program. Daniel Solove wrote about the ruling:

The 2nd Circuit panel concluded that the program was “reasonable” under the 4th Amendment’s special needs doctrine. Under the special needs doctrine, if there are exceptional circumstances that make the warrant and probable cause requirements unnecessary, then the search should be analyzed in terms of whether it is “reasonable.” Reasonableness is determined by balancing privacy against the government ‘s need. The problem with the 2nd Circuit decision is that under its reasoning, nearly any search, no matter how intrusive into privacy, would be justified. This is because of the way it assesses the government’s side of the balance. When the government’s interest is preventing the detonation of a bomb on a crowded subway, with the potential of mass casualties, it is hard for anything to survive when balanced against it.

The key to the analysis should be the extent to which the search program will effectively improve subway safety. In other words, the goals of the program may be quite laudable, but nobody questions the importance of subway safety. Its weight is so hefty that little can outweigh it. The important issue is whether the search program is a sufficiently effective way of achieving those goals that it is worth the trade-off in civil liberties. On this question, unfortunately, the 2nd Circuit punts. It defers to the law enforcement officials:

That decision is best left to those with “a unique understanding of, and responsibility for, limited public resources, including a finite number of police officers.” Accordingly, we ought not conduct a “searching examination of effectiveness.” Instead, we need only determine whether the Program is “a reasonably effective means of addressing” the government interest in deterring and detecting a terrorist attack on the subway system…

Instead, plaintiffs claim that the Program can have no meaningful deterrent effect because the NYPD employs too few checkpoints. In support of that claim, plaintiffs rely upon various statistical manipulations of the sealed checkpoint data.

We will not peruse, parse, or extrapolate four months’ worth of data in an attempt to divine how many checkpoints the City ought to deploy in the exercise of its day to day police power. Counter terrorism experts and politically accountable officials have undertaken the delicate and esoteric task of deciding how best to marshal their available resources in light of the conditions prevailing on any given day. We will not and may not second guess the minutiae of their considered decisions. (internal citations omitted)

Although courts should not take a “know it all” attitude, they must not defer on such a critical question. The problem with many security measures is that they are not a very wise expenditure of resources. It is costly to have a lot of police officers engage in these random searches when they could be doing other things or money could be spent on other measures. A very small number of random searches in a subway system of over 4 million riders a day seems more symbolic that effective. If courts don’t question the efficacy of security measures in the name of terrorism, then it allows law enforcement officials to win nearly all the time. The government just needs to come into court and say “terrorism” and little else will matter.

Posted on August 16, 2006 at 3:32 PM • View Comments