Killjoy Trojan deletes warez and smut.
In an article over at The Register , there is warning of a new trojan working it's way through the P2P networks.
From the article:
Virus writers have created a Trojan that deletes illicit files from compromised Windows PCs in addition to harvesting data from infected machines.
Erazer-A is spreading (albeit modestly) across P2P networks, where it poses as useful program files, or through chat programs.
Read more here.