Last I checked, Craigslist doesn't allow firearms to be sold on its site. That's one of the reasons I don't have too much use for it. What I don't understand is why this guy is suing them for allegedly hosting an ad that sold a gun he was shot with.
Even if the ad lasted long enough on Craigslist for the gun to be sold, it violated their terms of service. Also, if you were hit by a drunk driver whose car came from Craigslist, you'd have no suit. But this similar misuse is worth a ten million dollar lawsuit?
The only person at fault here is the shooter. You could try to make the argument that the seller knew he was prohibited, but it would be a hard sell.
I can only hope that this suit gets a decent jury. If this guy wins any damages from Craigslist, it'll be bad juju for anyone who will actually allow gun ads.