A California man has filed a lawsuit accusing Apple of violating US antitrust law because its iPhone forces buyers to use AT&T as their wireless carrier and the company "bricked" phones that had been modified to call over other networks.

Timothy Smith filed the lawsuit Friday with a California state court in San Jose seeking class-action status. The suit demands that Apple be barred from selling locked iPhones and that it be required to provide warranty service for owners of unlocked devices. The lawsuit also asks for unspecified monetary damages.

In the lawsuit - the second in as many weeks involving the iPhone - Smith alleges that Apple violated several California antitrust statutes when it tied the smart phone to AT&T and prohibited customers from using other carriers. The result, read the lawsuit, was that Smith paid too much for the iPhone.

"Apple forced plaintiff and the class members to pay substantially more for the iPhone and cell phone service than they would have paid in a competitive marketplace either for the iPhone or for AT&T's mobile phone service," read the suit.

Smith's lawsuit also claims that an exemption to the federal Digital Millennium Copyright Act of 1998 granted last year allows for phone unlocking and so should invalidate Apple's move last month to disable phones modified to work with non-AT&T networks. Moreover, said the suit, Apple violated consumers' rights by "bricking" unlocked iPhones with the 1.1.1 update it issued a week and a half ago.

"Apple acted in defiance and without sufficient consideration of consumers' rights to unlock their iPhones because it knew that the probable result of its update would be to render unlocked iPhones inoperable," the lawsuit charges.

Apple did not reply to a request for comment on the lawsuit.

Smith's lawsuit was filed by M. Van Smith, a San Jose lawyer who has partnered with another attorney, Damian R. Fernandez, to publish a website soliciting Californians for the class-action suit. The site, which uses the URL of appleiphonelawsuit.com, was registered with GoDaddy.com Inc. just three days after a woman from Queens, N.Y., sued Apple over the $200 price cut that CEO Steve Jobs announced for the iPhone in August.

On the site, Smith and Fernandez told iPhone owners they might qualify for inclusion in the class-action suit if they had paid a termination fee to their previous mobile service provider after they bought the phone, if their iPhone had been disabled or had had third-party applications erased after applying the 1.1.1 update. Four other situations also apply, said the attorneys.

Smith's lawsuit did not set a dollar amount for damages.