Ok, I am often outgunned and off target here. But I have to ask this: 1. If filtering is used, as suggested by someone, what happens to the small/mid-sized company that is multi-homed out of an ISP's /20 or larger block? In this case, I can see an ISP with a /20 bust that up to /21s smaller to accommodate this user. 2. Wasn't /24 filtering something that a few large ISP's did a few years ago and everyone complained? I don't have a reference here but I seem to remember some flack about that. 3. What happens in the case of a carrier that has given /24s to a downstream out of different blocks? I guess the real question is this: If X company can not be reached, how/who would you complain to? And would this be like the RR and AOL email filtering lists where we all complain, and this filtering is an effort by some to force others to clean up their act? Am I out in Left field? Jim