RE: AMA rule?
Well...
This kind of stuff is insane. I cant believe it when I read stuff like this. Grow up for cryin out loud. Some of these flyers are acting like absolute children.
If it was my plane, and someone ran off with it....they would get a written request in the mail asking for my plane back. If they didnt give it back, the next letter would be a subpeona to be in small claims court.
At the very least the club members should ban the thief from the flying field for unsportsman like behavior. Most club's memberships include a clause which says "Membership can be denied at the clubs discretion." or something similar.