Spammers practicing in the state with the greatest concentration of Net users may find it tough to conduct business as usual under landmark legislation signed by California Gov. Pete Wilson.

Aiming to curb one of the most detested practices on the Net-- unsolicited bulk email-- Wilson yesterday approved two controversial bills, one of which imposes the first mandate on spammers to label their messages.

Rep. Debra Bowen's (D-Torrance) bill requires unsolicited bulk emailers to put the label "ADV:" in the subject line of messages selling goods and services. Adult-oriented spam, meant for people over 18, would have to be labeled "ADV:ADLT."

The provision also requires that spammers set up a toll-free telephone number or accurate return email address so that recipients can request to be taken off a spam list. The new law does not apply to spammers who have an existing relationship with the recipient. But for those who don't, prosecutors would be able to seek up to $500 per email message or six months in jail for violations.

Wilson also enacted Rep. Gary Miller's (R-Diamond Bar) legislation to allow any email provider to sue spammers that trespass on their computer systems and to recover losses caused by network clogs or crashes. Under the law, providers can sue for $50 per unauthorized message-- up to $25,000 per day--- or they can sue for actual damages--- whichever amount is greater.

Miller's bill also makes so-called spoofing a crime. The practice is defined as "knowingly and without permission using the Internet domain name of another individual, corporation, or entity" to send bulk email.

Spammers often "spoof" return addresses with the domain names of larger companies, a practice which not only makes those larger companies look bad in the eyes of its customers but also can result in the larger firm's network getting clogged up with returned email.

"The advent of electronic mail has provided people throughout the world with an expedient and cost-efficient means of communication," Wilson said in a statement.

"Unfortunately, it has also created a whole new territory for the high-tech version of the door-to-door salesman," he added. "Together, these bills will protect Californians from the spam that clogs the arteries of the information superhighway."

Both bills go into effect January 1. Miller's provision applies to email providers that have equipment located in the state. Bowen's provision affects spammers who are located in the state or those who send unsolicited bulk email to computer users who reside in California.

"The Miller bill takes a novel approach to the problem of spam. It recognizes that an email provider has the right to decide how its private property--its computer equipment--is used," said David Kramer, an attorney with Wilson Sonsini Goodrich & Rosati who helped Miller's staff write the bill. "And when that equipment is abused by unscrupulous mass marketers, the Miller bill allows the property owner to seek redress."

California's spam laws follow statutes passed in Nevada, which require spammers to remove people from mailing lists upon request, and in Washington, which outlaws the practice of forging headers or hijacking other email systems.

But staunch antispam groups and some free speech advocates have problems with the new California laws.

For starters, critics say neither one will truly eliminate spam because perpetrators are often "here today and gone tomorrow." Bowen's bill is especially weak, critics say, because it depends on consumers complaining to state attorneys general who would probably only pursue a case if a lot of people complained. Even then, law enforcement would have to track down bulk emailers, who are known for their ability to disguise their identities and the origin of their email messages.

"I think it is going to be very difficult for the average individual who receives spam to find out who sent the spam--they usually include a forged header so you can't find out where it came from," said Paul Russinoff, state policy counsel for the Internet Alliance, an online industry trade group.

As the first person to sue a spammer under Washington's law has found, this makes it almost impossible to track down spammers to prosecute them.

In addition, civil liberties groups are concerned about Bowen's legislation hindering speech because it would impose the first mandatory labeling of Net content.

"There are going to be some concerns for civil liberties groups about the 'adult' label because it is segregating speech and other First Amendment concerns about how the labels affect commercial speech," Russinoff added.

A similar proposal was floated in Congress, but has now been abandoned. Free speech advocates argue that the Federal Trade Commission already has the authority to go after those who send false and deceptive email messages--and it has begun to do so.

"If they had passed only the Miller bill, I'd be praising California's legislature as the most Net-savvy in the country," said Jason Catlett, founder of JunkBusters.

"But by giving equal time to Bowen's bill, with its discredited opt-out model, they are looking just as confused as their federal counterparts in Washington," Catlett added. "Nothing short of a global failure in the generation of electricity is going to eradicate spam. By giving more power to ISPs, who are best-placed to fight spam economically, Miller's bill will become a big cannon in the war against spam."

But Bowen argues that labeling helps people screen out spam using software.

"The label is key, because it makes it easy for people who aren't technologically savvy to delete the spam without downloading or opening the message," she said in a statement.