Sorry to piss on bonfires etc, but I think anything which 'targets' (and I'm not being overly-dramatic or hysterical) one person/one thing smacks of bullying mentality to me. Whether he could/should handle it is a different matter, as is whether he brought it on himself (I happen to think he means well).
Imagine this in a different context; office twat (we all have one!) is mouthing off about how great he is as usual. Everyone else in the company has a quick conflab and agrees to say 'twat' after every sentence he utters. So everyone in the office is responding in this 'jokey' way. Would that be ok because the majority feel the guy is a twat? Or is he still entitled not to be bullied for being a twat (assuming he's not bullied anyone - which as far as I can see, Brand hasn't either).
I accept in advance that I'll be slated for being overly sensitive, but I just find it ironic that these boards on here are full of concerned parents with children being bullied or picked on. and yet us grown ups are happy to indulge in online bullying, and are able to justify it (lesson of the day; it's ok to target someone if we don't like them).