how can they be stopped?
IVARB, rip down the sign and defecate on it! I'm not a rabblerouser, just don't like people trying to enforce their will upon me. A group discussion would let you know if all your flying buddies want these rules or not. Why not hang your own set of anti-rules? 1) as many can fly as everyone is comfortable with at the same time. (If you're uptight by too many in the air, yell out "landing" and land!) 2) Fly as low as gravity will allow as long as the direction of your destruction is away from the flightline. (people tend to monitor their own investments) 3) Beginning pilots should seek the help of the more experienced, but should they be unavailable or unwilling to help, get a buddy (to drive you to the hospital when you slice open that artery from the prop) and learn on your own when everyone leaves the field. 4) The majority rules! By the way I fly at an AMA sanctioned, highly regulated and SAFE field, I love it that way, I go there by my own choice. That's what it's all about, choice, you can choose to leave or not fly there.