Many if not most cities or states have their own variants of the 10 codes..

This is a good forum to find out the deal in your state.. http://www.radioreference.com/forums/ There is a section for each state.

Some states have laws prohibiting the use of scanners in vehicles, but those laws must include an exception for licensed radio amateurs as that operation is regulated solely by federal law enforced by the FCC. That legal mechanism is known as federal pre-emption (of cities, states, rights to regulate) in areas that it is decided will be regulated solely by federal law. My mobile amateur radio will essentially pick up from DC to Daylight (well almost, 30mhz to 1ghz) excepting analog cellular frequencies which is restricted by separate federal law.

This capability has been used for public service by hams being asked to Foxhunt (or locate) transmitters interfering with licensed commercial, public safety or amateur frequencies. Our club has done training on this and has used it on one instance to find leaking cable TV service (which usually results from illegal taps). Since cable TV services can be hit with serious fines,since for example some channels on cable are in the aviation band which could cause havoc, they were very cooperative in repairing the problem when reported.

The FCC does impose legal limitations and can prosecute with federal charges on what you can DO WITH information heard on scanners and other equipment. Obviously using that information to aid and abeit illegal activity is one.