I think Bigtoad has got the right idea... The small amount of effort and organization it would take to acquire a registration slip would probably deter quite a few of the random campers that are responsible for chain sawing down live trees, and leaving there campsites in a *hit pile.
Hawgstoppah, If all ATV's and offroad vehicles are banned, where do you expect all those people to go and enjoy there view of the outdoors. I agree that it gets completely insane out there on the weekends sometimes with a bunch of young kids taunting death on the four wheelers, but do you think a complete is ban the right way to go about this? Where are they gunna head?
As stated above, ENFORCEMENT is key. Through random camping fee's, the government would be able to employ many more officers. more officers= more control=more fines= more cash to enforce!... its an viscious circle.
I dont think we can single out a group of offroad enthusiasts because im sure a lot of those guys take there kids out there and show them the "safe" way to ride and to stay outta the streambeds. We need more CO's to control idiots that are letting there ten year olds have free range with a 300cc machine. Forget who said it but I really do believe its gunna take a tragedy before anything is done about it.