After having downloaded a few mp3 songs, only to have them not launch in iTunes (nor QuickTime), I remember noticing at the time they were downloading that these specific mp3 files did not have a BIT RATE listed. Other songs in the same search had bit rates in addition to name of song, type, speed, etc., but there were a good deal of listings that didn't have a Bit Rate.

Those without the bit rates were the ones I happened to be downloading. They also were listed as having download speeds of "T3 or higher."

And each of one of them failed to load in iTunes.

When I would try to open the song in QuickTime or MPEG Streamclip or other programs, the programs refused to open the song. QuickTime said it was not a valid file.

I think then that those songs WITHOUT A BIT RATE listed are some sort of virus or spyware, probably designed for Windows users since the "songs" don't really do anything on Mac OS X. Someone out there is deliberately uploading these files with a bogus "mp3" extension on it. It could very well be an "exe" extension, which of course will not launch on Macs.

Again, just a theory...