False Suspicion and Cold Comfort

A post on the Washington DC/Metro Area Flickr users group has touched a nerve with readers of DCist, who are sharing stories of similar experiences in the comments.

D.C. area photographer “Yonas,” taking pictures in the Gallery Place Metro station, caught the eye of Metro Police who found it suspicious. They demanded identification and subjected the photographer to questioning.

This offends me about five different ways, but it provides a good opportunity to illustrate how suspicion is properly generated — and, in this case, how it is not properly generated — using patterns. The same concepts apply to the cop on the beat and the high-tech search through data.

I testified to a Senate Judiciary Committee hearing on data mining earlier this year regarding searches for terrorists and terrorism planning:

Pattern analysis is looking for a pattern in data that has two characteristics: (1) It is consistent with bad behavior, such as terrorism planning or crime; and (2) it is inconsistent with innocent behavior.

In … the classic Fourth Amendment case, Terry v. Ohio, …  a police officer saw Terry walking past a store multiple times, looking in furtively. This was (1) consistent with criminal planning (“casing” the store for robbery), and (2) inconsistent with innocent behavior — it didn’t look like shopping, curiosity, or unrequited love of a store clerk. The officer’s “hunch” in Terry can be described as a successful use of pattern analysis before the age of databases.

Recall that after 9/11 people were questioned and even arrested for taking pictures of bridges, monuments, and buildings. To common knowledge, photographing landmarks fits a pattern of terrorism planning. After all, terrorists need to case their targets. But photographing landmarks fits many patterns of innocent behavior also, such as tourism, photography as a hobby, architecture, and so on. This clumsy, improvised [pattern analysis] failed the second test of pattern development.

Photography on public property will almost never be suspicious enough to justify even the briefest interrogation. Photography is a serendipitous activity so it appropriately gets wide latitude. (Other facts could combine with public-location photography to create a suspicious circumstance on rare occasions, of course.)

It bears mentioning that regulations allow photography in Metro stations, but I don’t find regulation of this kind terribly comforting. It reminds me of Prague shortly after the Velvet Revolution, where I observed that people were consciously coming to grips with the revolutionary idea: “All that is not forbidden is allowed.” The prior state of affairs had been the opposite, “All that is not allowed is forbidden.” I hope this latter rule is not in force on our subways or anywhere else in this country.