A buddy of mine recently downloaded a movie (Scarface) off of Kazaa.
I introduced him yesterday to TDS-3 Trojan Scanner.
Today he was scanning his harddrive and TDS-3 recogized the movie as having a NTFS ADS hidden data stream.
I didn't have a clue what it was, other than it didn't sound good.
I went and researched a little and found the TDS-3 homepage to be more than helpful.
Read this site it's quite interesting.
So check it out you NTFS and Kazaa people.

http://www.diamondcs.com.au/streams/streams.htm

To get the best trojan scanner, IMO, go here and get TDS-3:
http://tds.diamondcs.com.au/