I have been using peer guardian since method first released it and its worth having it and i use it all the time...think that too many people are over paranoid about the RIAA.This is what they want,to install fear into the users....As for individual countries having different laws this is true...I'm in UK and they cant access your shared folder without your permission(anti privacy laws),so this favours us!!
The RIAA and others apparntly use companies to look for and take screen shots of stuff they want to prosecute for...so although using peer guardian will block known IP's...it isnt the only solution,but its one to try as nothing ventured,nothing gained.