Well, no. At least not before they do their 'trollwork'. If they get ignored, they might go away, or (if not) they will go further, with some more hardcore trolling, until they eventually get a reaction. And some don't go away if you ban them... They will make a new account, a new IP and go on with it, even worse than before.
I know of a troll on the TS3 site that cause lots of mayhem and drama. (with death treats and porn stuff) -.- He was 'put to sleep' by a couple of people who managed to track him down and let his parents know about his 'internet activity'.
Ignoring them doesn't solve things; banning them, not always; tracking them down to find out who they are, which in most cases scares them, is (most of the time) effective.