DoS of spam blackhole lists

Hi, Considering that it appears that spammers are now resorting to DoS'ing sites that host spam lists, wouldn't now be a good time to investigate the possibilities of a distributed, or at least, load balanced blacklist provider? Even something as simple as round-robin DNS with sufficient nodes (couple of hundred?) should be enough to make such attacks highly inefficient and far, far less likely to be effective. Of course, with round robin DNS, one can target the DNS servers. Would this make for an interesting community project? Any comments appreciated. -- Andrew G. Thomas Hobbs & Associates Chartered Accountants (SA) (o) +27-(0)21-683-0500 (f) +27-(0)21-683-0577 (m) +27-(0)83-318-4070