Tech-Recipes offers some Google search strings that dig up music that might be hard to find otherwise. One such string goes straight into FTP locations storing music files. I probably wouldn't share this if it were overwhelmingly piratical, by in experimenting with this string I found a lot of content that is being shared via the Web. Using the string bypasses the gunk of Web pages and goes straight to direct download locations. Here is what Tech-Recipes recommends:

-inurl:htm -inurl:html intitle:"index of" mp3

This string works only to find FTP locations left unprotected by password. The negative "inurl" tags force Google to ignore matches occuring on regular Web pages, and the "index of" string is very common to FTP directories. Of course, the string may be further modified, and MP3 may be replaced by other file types. Speaking theoretically, one could add a band name to the string and turn up unprotected songs. One question surrounding the ethics of this type of sharing would be whether an unprotected FTP directory represents an invitation to download, or whether doing so is stealing (bandwidth, not the music). In some cases the answer is provided by winding back through parent directories until you arrive at a Web page, which might turn out to be a music-sharing page—just as were so common and controversial in the pre-Napster era.

(Thanks to Search Engine Journal.)