Reading Declan's Politech list today, I was pointed to this article here about the problems with RBLs... which I heartily agree with. Our company, Neotonic, is blocked by SPEWS due to them blocking our entire colo, so we went to another colo... and by the time we had the colo set up (2 months or so), the new IP address range we were given was also SPEWS blocked. Of course, SPEWS is an unknown quantity at the best of times, given their anonymous nature, but "they" are always telling you on NANAE that the correct thing to do is to choose an ISP that doesn't get listed... but that doesn't seem to be possible. Vigilantism at its best...