Heh :-)
This is some great use of search-engine result mash-ups:

http://www.blogmusik.net/

Do some clever google-querying (for example -inurl:(htm|html|php) intitle:”index of” +”last modified” +”parent directory” +description +size +(wma|mp3) +”artist name” )
Slap on a nice flash interface, and Wham:
you got a streaming music app that makes a HUGE music-libary instantly available, while using other peoples bandwith, and without doing something illegal ...

Brilliant !