Yeah, we have had our share of embarrassing fans to be sure; the brick thrower you alluded to, the tree killer, the one's giving Golding's kids a hard time, 24&7, etc......
It is the lunatic fringe of fanatics though and because it's "Bama" it seems to be magnified more. I mean, LSU and Tennessee fans have been known to comport themselves with the very best of behavior. Gator fans have been known to throw piss filled baloons at the leg humpers and the leg humpers have been seen trying to rip off our National Championship flags. Hell, as a matter of fact, the only fanbase that doesn't go off half coscked like most is Vandy fans and in Nashville, it just doesn't mean more most of the time (with the rare exception of baseball).