When someone's hitting the site as blatantly as they are now, I think it's about time guest access posting (not viewing so everyone can still see how good the forum is) was banned. Sure you could argue that spammers are going to make fake accounts anyway, but the kind of thing that's happening at the moment looks like a bot has stumbled across the forum... the bogus posts don't even read like they are aware of the audience. Can we have one of those "type the characters you see here into the box for verification" features?
When the entire list of "Last forum posts" is swamped out by spam, it justifies a change.