Michael Martin, Well Said!  The prime directives of scanning!  This is the exact advice I give to new listeners.
Thanks!
Rule 1: Do not make it obvious you have a scanner in your vehicle
Rule 2: Do not look like a porcupine on your car (Multiple Antennas) - See
Rule 1.
Rule 3: Do not FLAUNT your scanner equipment to anyone and everyone - See
Rule 1.
Rule 4: Do not show up at ANY crime scene and have your scanner blaring -
See Rule 1.
Rule 5: Do not do ANYTHING that will get you noticed by law enforcement -
See Rule 1.
Rule 6: Do not SPOUT OFF anything to a law enforcement officer about the
legality of/your rights - See Rule 1.
Rule 7: If you are pulled over/stopped by a law enforcement officer, PLEASE
turn OFF your scanner - See Rule 1.