Posted on a forum of which I am a member, about the RIP Moat facebook pages. In reply to a call for them to be banned.
As far as I can tell the page that was removed was done so because it breached the T&Cs of facebook (I believe there were comments inciting violence). The problem with banning this sort of group as you seem to suggest, is that you won't actually be stopping people from thinking these things. You just won't be able to search for them. I actually think it's quite a good thing these pages exist, because then you know who the nutters are!
The far more pertinent question is surely what drives people to want to join this sort of group? If you take the group away, those people that are publically sympathising with Moat will instead do so in private. What makes tham sympathise? A few of the crazies that joined his group may be dangerous, they will continue to be so regardless of whether they can announce it on facebook.
I still blame it on the media. I think the prolonged coverage made him an obvious 'anti-hero'. People want to be famous, and if they can't sing / act / kick a ball then suddenly this new route to stardom has emerged. Terrifying really.
While I don't agree with the banning of internet pages of this ilk, I have no problem with what Cameron seems to have said (not heard his words directly). This is a case of someone with influence offering an opinion, I'd rather the PM (of any party, except the obvious) use this influence than the papers that try and do it on a daily basis*.
*This bit refers to something that the PM said in PMQ's expressing his distaste for the facebook groups.