And this is surely in the running for lamest ACLU objection to the use of new technology to make people safer -- there were no "longitudinal" studies before deployment, and looking at an abandoned backpack might lead to racial profiling --
“If a 911 caller reports that someone left a backpack on the sidewalk, will the camera image of someone who appears to be of Arab or South Asian descent make police decide that person is suspicious?” asked Ed Yohnka of the American Civil Liberties Union of Illinois.
[Apparently the ACLU can differentiate Arabs and people of South Asian descent from Italians, Turks, Latin Americans, and George Hamilton, even on a small screen from hundreds of feet away, and apparently even after the suspect has left the area. Impressive!]“There seems to be this incredibly voracious appetite on the part of the city to link up cameras to the 911 system,” Mr. Yohnka said. “But there are just no longitudinal statistics that prove that surveillance cameras reduce crime. They just displace crime.”