The next time you use the "An IP is not a person" defence and say someone else must have broken into your network to download. And the RIAA lawyers say that's bullocks. Feel free to use this example:
FileSharing Talk - RIAA and Homeland Security Caught Downloading Torrents
And make sure to have them pay special attention to their defence:
FileSharing Talk - RIAA: Someone Else Is Pirating Through Our IP-Addresses