The idea is simply that Carreon's current complaints are almost utterly meritless, but if he's hacked or unlawfully slandered, his claims actually do have merit; even if they won't in the end be held against Matthew Inman, it'll still be a drag on everyone to sort them out.

Maybe not so much legally, but in any other way it might not work so well. It only takes someone to summarise the course of events as "Inman incites mob to exact revenge on audacious lawyer", and suddenly Carreon is the victim.

Of course, the mob's lust for blood achieves nothing but self preservation, and even if the claims are baseless, we're observing each day the consequences of its actions; mostly in the form of Carreon building up his case with ostensibly supportive evidence, and dragging other websites into the fray who had no involvement except to allow people to comment.

But, I dunno, I'm not the greatest advocate of internet vigilantism.

I agree it doesn't make any sense, but the fact of the matter is that even judges commit the fallacy of guilt by association, without being aware of it. If hundreds of assholes and a dozen criminals support you, then that makes it seem more likely that you are an asshole or a criminal. Statistically that is probably even correct, even though it's still guilt-by-association in an individual case.

  >  If hundreds of assholes and a dozen criminals support
  > you, then that makes it seem more likely that you are
  > an asshole or a criminal.

I'll bet there are a lot of criminals/assholes that like watching The Colbert Report. If they do illegal (or douchey) things on behalf of Stephen Colbert, does that mean that he can be personally held accountable (assuming he doesn't make a call to action on-air).