Napster

What are they:  Napster is a peer-to-peer file exchange programs.

What they do:  It is used to exchange files of both copyrighted and public material.  A large majority of the material exchanged is copyrighted.  All material is discovered from a central server, but downloaded from user machines.

Are They Popular:   It used to be.  Alot!

Napster is Illegal:
Napster argued that it could block more than 99 percent of all infringing song files. But Judge Patel told Napster it needed to block 100 percent of unauthorized copyright songs or stay offline indefinitely.