Being that a lot of people do not think a size filter alone would actually work, how about making a hash filter along with a size filter?
maybe in conjunction with an ip filter would really put these people in a really tight spot....
Let's see what people really want....

The problem with banning ip's is that ip's change. Particularly but not only dynamic ip's change. So a person may ban a person one day, the next day or few later after their ip has changed & someone else adopts that ip they find they can't connect to a lot of downloads. And the person whose ip changed to a new one is no longer banned. I've never been in favor of ip banning for those reasons. Particularly since some people may be banned when they didn't deserve to be. Perhaps a connection issue between them or something they accidentally downlded etc.