It's a well-known secret that the RIAA and MPAA contract third parties to employ a number of methods to inhibit illicit file sharing, including denial of service attacks and hiding spyware as music. But these tactics have become less effective, forcing one such company to cease operations.

Following the shutdown of Napster, Gnutella and other decentralized services sprang to life and peer-to-peer file trading became a seemingly unstoppable phenomenon. But even though legal action couldn't stop P2P, the record industry decided to do the next best thing: disrupt it.

Earlier this year, Overpeer was even found to have been planting adware that caused pop-ups within files named as popular music downloads. These fake files are considered one of the primary reasons Kazaa's FastTrack network has become almost unusable over the past year.

But the success has also made the future murky for these companies. With users migrating to new technologies such as BitTorrent, such actions aren't working like they have in the past. The RIAA has also turned up the heat in the courtroom by going after users directly, shifting the focus away from the P2P networks.

On Friday, Overpeer owner Loudeye announced it was shutting down the subsidiary's content protection business just a year and a half after acquiring it. Loudeye said the closure would cut $1.6 million from its quarterly costs.

MediaDefender and MediaSentry, on the other hand, opted recently to find suitors in order to stay afloat. MediaDefender, which does not publicly advertise its services, was acquired in August by ARTISTdirect for $42.5 million in cash. MediaSentry, meanwhile, was purchased by SafeNet in June for $20 million in cash and stock.