wrt excessively zealous enforcement, it may be the case that more efficient police work improves the situation. Right now, the police have an incentive to arrest somebody even if they aren't sure who to arrest. If technology means they can arrest more real bad guys more easily, there won't be so much pressure to bend the rules.
Is there any guarantee in place that one of them might be attached to an innocent persons vehicle, only to have some budget-desperate bureaucrat decide to datamine his departments last 2 years worth of archived GPS tracking data in search of fineable offenses?
"Your car was detected exceeding the speed limit 63 times on 101 southbound on weekday mornings, and 59 times on 101 northbound on weekday afternoons between 01 Jan 2011 and 31 Mar 2011. We are offering you a one-time opportunity to settle all 122 speeding offences for $45 each, a 75% reduction on the minimum fine amount, if you pay $5,490.00 online by creditcard and waive your rights to appeal by 5pm on Fri 11th Nov. Failure to pay in full by Fri 11th may result in issue of 122 speeding fines @ $180 each resulting in a total fine of $21,960.00. Regards, your local cash-strapped local government area police department."
I would tend to think that investigations are "active" or "not active", have case numbers, have a process for being closed and open probably documented in the police General Orders or whatever the FBI equivalent is, and I think the police should not be able to retain information from vehicle telemetry past the closing of a case unless they are actual format subjects of the investigation, and then only consistent with the existing policies on retaining information.
I DO NOT think it is reasonable to use GPS telemetry to passively fine people for speeding or running red lights.