The swear filter usually gives you a warning, then watches you for the next 24hrs. Least time time I set it off anyway.
The ones that come out of the blue are the anonymous jerk... erm, arena monitors. Haven't heard anything about them losing thier power or anything, and I still get muted for no apparent reason sometimes (and for apparent reason other times
).
God help ya if one decides he doesn't like ya. Yer AH life becomes hell, and they aren't accountable since they're anonymous.