I agree with Lego. I don't believe an approach like that will work due to ip's being so easy to change. I can't think of a reliable way to block anti p2p people, hence you sparked my interest Hero! Don't lull yourself into a false sense of security tho, and unless you trust what they're writing into the code you're running, you MIGHT be opening yourself up for more problems?
Lol - and I still run kazaa??? roflmao - i am da n00b!