Sex offenders in California would be barred from using social networking Web sites such as Facebook and MySpace under a proposed law aimed at making the Internet safer for children as more and more of them flock to the Web.

San Francisco D.A. Kamala Harris sponsored the bill introduced by Assemblywoman Norma Torres. (Photo: Mike Kepka / The Chronicle)

Citing horrific cases in which children were sexually assaulted by men they met online, Assemblywoman Norma Torres, D-Pomona (Los Angeles County) introduced the bill last month, which would make it a crime for Californian's 63,000 registered sex offenders to use any social networking site. The proposed law defines those as a Web site "designed with the intent of allowing users to build networks or connect with other people and that provides means for users to connect over the Internet."

Assembly Bill 2208 is similar to legislation passed last year in Illinois, but doesn't go quite as far as a New York state law that additionally requires sex offenders to register their e-mail addresses and online aliases with state authorities, who can then turn over the names to the companies that run the social networking sites. After the New York law passed, 3,500 sex offenders were purged from MySpace and Facebook by the Internet companies.

All of the laws depend to some extent on the assumption that sex offenders will police themselves.

San Francisco District Attorney Kamala Harris, who is sponsoring the measure, acknowledged that the proposed law isn't a fail-safe measure, but said it will offer a deterrent to sex offenders who do not want to return to jail. Harris, who specialized in child sexual assault cases as a courtroom prosecutor, said it will also create more public awareness around the issue and give law enforcement another tool.

"The carrot is don't get on these sites, and the stick is we will prosecute you," said Harris, who is running for state attorney general. "In my experience, these types of predators are a slimy group and they don't want to go to jail, and what we're telling them is that if you go online and start chatting with my 12-year-old niece, you're going to jail."

The number of users on social networking sites has doubled since 2007, Torres said, and many of those users are children. She noted that just last month, a 33-year-old man lured a 12-year-old girl to a hotel in Anaheim, where she was sexually assaulted.

Facebook attorney Chris Kelly, another attorney general hopeful, said the law is a good first step but noted that it is often difficult for social networking sites to identify sex offenders without knowing how they identify themselves online.

"It's a good start," he said. "But it needs to be strengthened."