U.S. state and federal officials are scrambling to deal with a rising tide of spam, according to data published on Wednesday.

In 2007, the U.S. Federal Trade Commission (FTC) reported 221,226 Internet-related fraud complaints in the United States, or 16,000 more than in 2006.

Even so, the numbers probably underestimate the total number of complaints, and in many cases consumers are not aware when they have been victimized, said authors of the report published by the San Jose Mercury News on Wednesday.

California collected 8,622 individual complaints of Internet-related fraud - almost twice as many as New York, the second-ranking state, the report said.

Most complaints (5,629) focused on possible identity theft, service disputes, spam, spyware and "phishing," or e-mail scams that trick recipients into revealing personal information, said the report.

The other 2,993 dealt with equipment and software problems. Together these accounted for 14 percent of all consumer fraud complaints received by the state, according to the report.

The impact of Internet fraud on consumers and legitimate businesses is considerable. Last year, an estimated 7.1 billion dollars were lost to viruses, spy ware and phishing, said the report, quoting data provided by Consumer Reports, a non-profit organization.

"The states and the FTC have limited resources, but this problem is getting worse over time," said Reece Rushing, director of regulatory policy at the Center for American Progress. "It's a low priority in many states."