Eject early and often?

[akalsey]

Garth, how do you eject someone who's walking away, making quiet barbs out of earshot of everyone else, and generally being a model citizen in public while jabbing daggers at you in private? I don't want to look like the agressor or like I'm tossing someone just for the heck of it.

I'm not saying it can't be done or that you shouldn't, but I'm looing for some concrete methods for doing it.