Problem: You just received a letter from the RIAA/MPAA--you're being sued.
Likely Cause: We're not here to judge.
The Fix: Resist the urge to drop your computer into a lake, format your hard drive, or steamroller your iPod. The only appropriate action when served with legal papers is to call a lawyer. You can find a nearby attorney who handles this type of lawsuit by browsing through the list at this online Directory of Lawyers Defending Against RIAA Lawsuits.
How to Avoid It Next Time: Make sure that your wireless network connection is secure and that media folders are not shared on your PC. After the dust settles, uninstall from your system any peer-to-peer applications that don't check for copyright.