Well, you have to remember that some people live in areas where a lot of stuff goes on! Heck, I could probably get by with just one scanner, BUT, if you want to hear everything that goes on you need between 2 and 20 scanners! Some need multiple trunking scanners for different systems that are in their area. Some listen to Milair - so you need 2 scanners for that, 1 for VHF and for UHF. If you're in a busy area you might need 1 scanner for the city police, another for the County Sheriff and yet another for the State Police - God forbid you want to listen to Fire or EMS on top of all that!
Understand now illinois_skywarn_spotter???
Mike