http://fusion.net/story/107298/is-nycs-new-gunshot-detection-system-recording-private-conversations/ The system is recording two seconds before the gunshot and four seconds after. It's been used to convict at least one murderer because the recording caught the victim speaking his murderer's name. The company and officials state there is no expectation of privacy on a public street. ----- My comment: in order to record two seconds prior to the gunshot, the microphones must be recording ALL THE TIME. I say this because I'm familiar with video/audio recording used in education. Even though you hit pause, it continues recording, allowing you to go back and "add/edit" the "paused area." For example, after you hit pause to take a break, a student or visitor asks a question, and you think "that was a good question; wish I had still been recording--oh, that's right, it's still recording." Again, no one and no technology can predict when a gunshot will happen. To record two seconds before, the recording must have already been in progress. It's my (educated?) guess/assumption that the recording is always happening. When the system recognizes a gunshot, two seconds before and four seconds after are saved to a different hard drive. When the primary drive fills up, the system starts recording at the beginning of the storage drive, over-writing previous recordings. At least, we hope they're being over-written and not saved. Folks, I bring this up to emphasize our slow creep to the fruition of Bentham's vision and Orwell's nightmare.