As mentioned in a previous blog, just how bad kazaa and limewire are, now it appears even Bit Torrent has been hit with spyware, but nothing like what you get with kazaa as mentioned in this article from eweek.com
Just remember, if you are going to use file sharing programs you are going to have to double up on your spyware scans and even there is no guarantee that you will get rid of it all through normal measures either. You can always get a copy of the latest spyware scanners from the SOFTWARE/SUPPORT section of this website.
