if you got those files off FastTrack (Kazaa, Grokster, iMesh) and they do turn out to be fakes, there's a Fakes forum at FastTrack Central.
people post the file size (in KB, as shown by Kazaa/Grokster) of the fake, so other users can avoid by comparing with their search results. (file names are too easy to change, but the file sizes of fakes are more permanent markers).
FTC's Fakes Forum
Fake Movie List I put together from all those posted.