Ok... If we place an ip filter would it work against dynamic ip's, or ip changing software? and a hashfilter along with a size filter? we need to do something about this. Even if spam gets bigger, who will want their computers uploading huge files constantly? I think a passive size filter on the user end would help. A hash verification process would be even better as you said along with a size filter on the user end would probably be the best way to go, Bitzi has done an awsome job at identifying files by bitprints, why not use bitzi then to filter out of the network alltoghether files with prints that have negative comments, or are confirmed corrupt, a virus, etc....?? let's say after receiving 6 negative comments, a file gets banned... or reviewed and banned...
I think it is worth a try, maybe they should just do it and see what happens.

An IP Filter won't work as well on dynamic IP's as static IP's, but it will help as dynamic IP's are usually rotated (there may be some casualties, but they can always get static).

The hashfilter will only work on known bad files, but still a large improvement. It will make the spammers and MAFIAA have to work even harder to mess up Limewire (Far to easy as it is right now)

The filesize filter will make them have to make larger bad files which in turn will need longer to download taking up their bandwidth and slots

All three together would give them a real headache