If you're familiar with the sites AOL was offering (Homestead I think it was??), it's similar to that idea where it's open to anyone, anywhere... therein lies the problem...
Looking quickly, it looks like there's 2-3 new ones per day average.
It looks like there must be a BB somewhere that alerts people to free web space. I agree with Scott, chuck them. I bet, even a small charge, would make 99% of the problem go away but there is really no good reason to do it. Web space is pretty cheap just about anywhere.