Tim,
I was once playing at Broadmore GC in Portland (a daily fee course). The group ahead of us is playing like a banana slug. Well, I was a lot younger and more stupid, so I yell at them, "Come on, get moving" on a par 3. Guy drives back and looks like he wants to beat the crap out of me. Fortunately, I'm a lot bigger than he is and he just yells some silly thing questioning whether or not I liked girls. I replied with something pretty funny and we all start laughing. Guy gets so irked he drives his golf cart over the green.
But it's not limited to public golf. Across the street from Broadmore is Riverside GC (H. Chandler Egan). I'm a member there, and it's a nice, friendly club with a few wacky members. One of these nut jobs tees off on #13 and is upset because there's a prison next door, and the guys are making noise on the outdoor weight machines. So the member decides to show the prisoners who's boss and helicopters his driver into the prison rec yard. Needless to say, you don't want to give prisoners a golf club, and the guards call the county sheriff who proceeds to greet our friend on the 18th green for a nice escorted trip "downtown".
Idiots come in all economic groups...