P2P Software Kit
If you're involved in P2P file-sharing, you may be using GTK-Gnutella, or some similar application. You may not be aware of it, but when you registered as a P2P software user, you probably agreed to let the network use your computer as a distribution source of music files. In other words, not only are you illegally downloading files, you are also illegally distributing them.
If you want to do the right thing and, not incidentally, keep strangers out of your hard drive - you should disable your P2P software's uploading capability. Go to the Illinois Institute of Technology website for information on how to disable file sharing in a number of programs.
NOTE: Some peer-to-peer software and services make it difficult for you to de-install them. We can't make any guarantee how this will work on your particular system, so be sure to back-up your data and other applications first to avoid any loss.