One problem for site owners is that the definition "trolling" can be in the eye of the beholder. As some of you may well know, it isn't uncommon for the phrase "tory troll" to be bandied about on Comment is free in the direction of anyone who dares to disagree with what can be perceived as the "party line" of the paper. Disagreement, though, isn't trolling in my view. Moderation can help, although it can also be divisive. I think of moderators as being analogous with referees in football - of course they sometimes make mistakes, but then they wouldn't be having to make decisions at all if the players weren't constantly trying to circumvent the rules of the game. And, of course, newspaper comment sites aren't averse to publishing pieces designed to be extremely provocative. It is surely no coincidence that James Delingpole actually rhymes with "troll", a gift to limerick writers the world over.