California OKs toughest anti-spam law in nation

"I don't think that states have much business regulating the Internet," he said. "If you can't tell where the recipient of an e-mail is, and still have to comply with different state regulations, it is a burden on interstate commerce."

But if the law survives challenge, it could well have a significant effect on spam. Coming from the nation's most populous state and the home to many large Internet companies, the new law would put a burden on the sender to determine if the recipient resides in California, a technically difficult task.

"California represents up to 20 percent of the e-mail that is sent or received," said J. Trevor Hughes, the executive director, of the Network Advertising Initiative, a group of technology companies that send e-mail for marketers. "Instead of trying to segregate the California e-mail addresses, many of our members are going to make the California standard the lowest common denominator."

Until now, state laws against spam have largely tried to ban deceptive practices in commercial e-mail-like fake return addresses. Many require that spam be identified with the phrase "ADV" in the subject line. Only Delaware has also banned sending unsolicited e-mail. But that law can only be enforced by the state attorney general, who has not taken any action under the statute.

Action under the California law, by contrast, can be brought by the state, by e-mail providers that have to handle spam, and by the recipients themselves. At a news conference in Sacramento on Tuesday, Kathleen Hamilton, the director of California's department of consumer affairs, promised to enforce the new law, when it goes into effect on Jan. 1.

The law's proponents argue that the right of individuals to sue represents the most important form of enforcement.

"A few well placed pieces of litigation can do wonders," said Debra Bowen, a California state senator from Redondo Beach, who had proposed anti-spam legislation similar to the new law.

But e-mail companies are already preparing for an onslaught of lawsuits they say will be frivolous.

"Small claims court will be filled with people suing legitimate marketers saying they don't remember signing up for this list," said Kenneth Hirschman, general counsel for Digital Impact, a big e-mail marketing company in San Mateo, Calif.

"The companies will have to drudge down to the court and say here is the evidence that this person has opted in."

The law allows companies to send commercial e-mail to their customers, to those who have inquired about products or services, and those that have "expressly consented to receive e-mail advertisements from the advertiser."