So you put in one of those 'fill in the text' or 'who is this?' filters like so many other sites. Doesn't have to be complicated, just something a 'bot can't get past. Or just a 'report abuse' button with a 4-clicks-and-it's-gone function. I would guess that it's part of the site package already, but just hasn't been implemented. While it was just haiku spam, it was one thing - but now it's getting to be porn. I run into enough of that elsewhere, this has been a refuge from that sort of thing . . .
The Truth Will Set You Free. But First It Will Piss You Off.