>many think SORBS should not be used, >including www.dnsstuff.com I know that this doesn't answer your main questions... but..
I would agree that SORBS should not be used for outright blocking. However, I personally wouldn't even use SBL or XBL or DSBL or anything else for outright blocking... but, yes, SORBS is a bit more risky for FPs than the others I've mentioned. But I do use all of these as "factors" which I weight into the score. (and I think that the warning from www.dnsstuff.com has more to do with people "outright blocking" based ONLY on that one RBL's results) --Rob McEwen