Saw a post on /. that mentions how this app...
http://www.furthurnet.com/
Uses file checksums to verify files that are being traded.
Never heard of furthurnet before, it says its a legal music trading p2p app.
Haven't bothered trying it though, as I prefer illegal music trading aswell as movies. Simply because it pisses the RIAA off.
Has anyone tried it out? Post back if you know what the heck furthurnet is, and if its any good.