i don't think with blocking ips you will help the community any further. you never know: it could be a new user (who simple hasn't got anything to share yet) you're blocking, thus making the community less attractive. just imagin you start using the gnutella network and everyone blocks you?!? so keep sharing - they will either realise the spirit, or they won't. but it is surely not worth my and your time to keep looking at who is downloading, what is he sharing and should i block him or not ...

long live p2p