Well...
I'm not against calling out someone for trolling (although this would obviously be reviewed on a case-by-case and you are better off reporting them). I do have an issue with insults and name calling however.
That said, it doesn't always require a stern hand, so that too would be handled on a case-by-case basis. It also depends on the severity of the one trolling. So, much to the agreeance of folks who brought up online harassment, I would always advise looking at the totality of a situation before calling someone a troll.