There's been suggestions the RIAA or other groups not happy with p2p sharing are responsible.
See these links: 1. autogenerated spam results, & also this one: 2. autogenerated mp3 spam results
Also to be aware of is certain other file sizes; see WARNING: Viruses on network you should be aware of!
Don't let yourself get confused between KB & MB. For music & video, all files should be over 1 MB at least. You can double-click on the top of the size column of the search results so it arranges the files by size with the largest at the top & those KB files at the very bottom of the list. A file size filter would be handy but it hasn't been added to LW. Phex has one. Depending on which gnutella program you're using.