Cool post for the Peer Guardian thing, I'll have to look into it. Anyways, the best option if you're worried about government agencies catching you would be to not share at all. Even sharing one file that is under copyright will get you in jail if your government has anti-piracy laws. Some countries are more lenient than others. For example, the US prohibits sharing and downloading of copyrighted files. Currently, Canada, where I live, allows people to download copyrighted files for PRIVATE use only. Sharing them, whether it be through use of P2P applications or plain ol' CD/DVD burning is illegal. Follow the rules, and remember that age old saying...

"If you've done nothing wrong, you've nothing to fear."