1. Camera vendors and cities often put cost-neutrality clauses in their contracts. It's illegal in California yet cities still do it. Check with your state.
2. Some cities will shorten
yellow lights at camera-equipped intersections. In some cases those actions are illegal as the yellow light times must conform to the engineering surveys performed.
3. On some tickets there will be instructions to not contact the court. It's a way for cities to harass vehicle owners into giving up the identities of the real drivers.
4. Again, your state may be different, but California requires a 30 day warning period when a camera is online. Some cities ignore this and issue only 30 days warnings for the first camera installed, not for every camera.
5. Some camera tickets are sent without proof of service - this leads to denial of due process.
6. Some contracts have explicit quotas.
7. A lot of cities are now enforcing left and right turns instead of straight-through movements. It's purely profit driven.
Here you will find more information about why photo enforcement is bad:http://www.motorists.org/photoenforce/
And here is one California specific web site:http://www.highwayrobbery.net/