Nothing here compromises your privacy, and nothing will artificially incriminate you. Everything is already public information.
A system like this would be exactly the same as photos being released to the public by the police (which they have), and then random people ringing up saying "That person might be XYZ" (which also happens).
This would be a simple automation of the process to help filter down who it could potentially be (none of the results would be public). It would be up to the police to work out who should be pursued.
Also, I entirely disagree with your statement that technology is the cause. Riots happened before the Internet and social networks. People would be using phones, radio, and word-of-mouth anyway.