1) every radio would vary if it would leak at all - you would basically see them beside you.
2) if you mean uniden beatracker warning system - not very reliable.
3) you would need to use a spectrum analyzer and have access to a police car to find the leakage - not easy to do, we have this...
Yes Fixed cameras are already used in California Arizona NEW mexico Ohio MD DC and a few others.
We made a device for all these cameras http://www.navalert.com
Chris