Amending this with another Ham license benefit:

A number of states have laws restricting the use of scanners. Just to listen.

Most but not all of the states that do restrict use, have a carve-out for licensed Hams, The restrictions seem mostly to be against mobile use or by certain people or only allow certain people.

NY is extra nasty with an outright ban on possession of a scanner and an ambiguous law. The law seems to allow use by licensed Hams or create problems for Hams who would otherwise be in compliance with the laws of the other 49 states. The NY law itself may be illegal because the Federal Law / the FCC control radio at the federal level. The local officer on the side of the road might not have read the Federal law or FCC regulations.

Start here: http://www.fireline.org/scanlaws/index.html and click on "State Scanner Laws" on the left hand side.