The lawsuit, filed in a federal court in Chicago, accuses Web site administrators Mike Greiling of Eden Prairie, Minn., Will Glynn of Davie, Fla., and others of knowingly infringing on Tecmo's proprietary software for the games, which run on.
Greiling could not be located for comment, and Glynn was not immediately available. The site in question, www.ninjahacker.net, appears to have been abandoned.
Tecmo, a Torrance, Calif.-based subsidiary of Japan's Tecmo, said it has launched an investigation "to find and identify all offenders in this case." The lawsuit charges the defendants with violating theand seeks unspecified damages.
"On behalf of the game industry, the gamers and all future innovations in gaming, the protection of intellectual property is a serious issue that affects everyone in the game industry, and can no longer be ignored," John Inada, general manager for Tecmo, said in a statement. "Ignoring the situation will ultimately hurt future gaming experiences for both casual and hardcore gamers, which is why Tecmo must take action to protect our intellectual property."
Some of the most popularcirculating on the site were for "Dead or Alive Xtreme Beach Volleyball," which features scantily clad women. The hacks created new "skins" for the characters, rendering them naked.
The publisher posted a warning on its main Web site last year vowing action against those distributed the hacks. "We're watching you very closely!" the notice read. "Please do not post anything about nude patches and other hacked information or you will be punished to the fullest extent of the law...So far we're tracking one suspect, anybody care to be the second?"
Tecmo's parent company won a similar case in Japan two years ago in which it sued distributors of a naked hack for the action game "Dead or Alive II."
Reuters contributed to this report.