Grokster

Grokster is a peer-to-peer file sharing utility that uses an interface similar to Kazaa, and combines searches over several P2P networks.

The Grokster software contains adware, which lead to the creation of Clean Grokster, a third party version of the software without ads. Grokster aggressively pursued distributors of Clean Grokster, sending out cease-and-desist orders and shutting down websites.

External Links:

Grokster's homepage (http://www.grokster.com)