Sony is attempting to block access to the PS3 hacking tools developed by Geohot and others, requesting a temporary restraining order and claiming that the TPM-circumnavigating system has already been used to pirate games. According to copies of the complaints at Geohot's site, Sony is demanding that all mention of the tools and the tools themselves be taken offline, as well as the impounding of Geohot's own equipment.
According to Sony, Hotz's hack efforts violate the DMCA, the Computer Fraud and Abuse Act, "and has alleged contributory copyright infringement arising out of the Copyright Act; as well as related state and common law claims for violation of the California Comprehensive Computer Data Access and Fraud Act, breach of contract, tortious interference with contractual relations, trespass and common law misappropriation." Much of that seems to be to do with Hotz's contravening of the PlayStation Network terms of service and user agreement.
For now, Geohot has moved his frontpage with details of the PS3 hack, but it remains to be seen to what extent Sony's demands will be allowed by the court. Any real legal action would seem like shutting the stable door after the horse has bolted, however; the hack is in the wild, now, and it's hard to imagine anything Sony could do to reverse that.