"Wireless communication is an emerging technology," Davis said in a statement. "We are acting now to prevent spam text messaging from spinning out of control like spam e-mail has."

The bill does not provide for any direct fines or penalties against companies that spam mobile users, according to a spokesperson from the office of Assemblymember Tim Leslie (R-Tahoe City), who sponsored the bill. Instead, those people who receive mobile spam will be able to sue the sender to recoup the money spent to receive each unwanted message under an existing state unfair business practices law.

Unlike wireline e-mail users who usually pay a flat rate for all Internet services, people who elect to receive and send messages on various wireless devices almost always pay extra fees for the service.

Wireless industry spokespeople were not immediately available for comment.

Davis also addressed junk faxes and telemarketers in two other privacy-related technology bills that he signed on Thursday (related story). One allows the state to enforce a federal law that bans unwanted ads that make their way into offices and homes via fax machines. Davis has already signed legislation that required junk faxers to provide a toll free number for consumers to call if they wanted to opt-out of receiving junk faxes. AB 2944 strengthens the law protecting Californians from junk faxers.

"There are few things more irritating than a fax machine that won't stop ringing," Davis said. "It's especially frustrating when those faxes are unsolicited advertisements. This bill will restore some peace of mind to those of us who are bombarded by paper."

The other bill strengthens a "do-not-call" law already in effect that lets consumers place their names on a special list to avoid unwanted telemarketing. The latest bill clarifies the law to allow small businesses to pay reduced rates for the "Do Not Call" list and ensures that the Attorney General will be able to implement the program on time.

"These days, telemarketers and advertisers are intruding on everything -- our home phones, our cell phone, our fax machines and our pagers," Davis added. "Today, California cuts the line on unsolicited faxes, phone calls and text messages."