YNOT – Two California men have sued Netherlands-based tube site YouPorn.com of spying on web surfers in violation of U.S. law.

David Pitner and Jared Reagan, of Newport Beach, Calif., accuse Midstream Media, the owner-operator of YouPorn, of engaging in deceptive and unfair business practices and of unlawful and unfair competition under the U.S. Computer Fraud and Abuse Act and California’s computer crime law.

Filed in a California District Court, the suit alleges YouPorn “intentionally access[ed] plaintiffs’ … computers without authorization.” At issue is an invasive practice known as “history sniffing,” in which websites employ code snippets to detect where a visitor has been on the web. Security experts consider history sniffing a potentially disastrous invasion of privacy, and Mozilla will incorporate technology to block the practice in Firefox 4.

Regardless, a number of websites employ some sort of sniffing code. Researchers at the University of California at San Diego recently reported (PDF) that of the top 50,000 Alexa-ranked websites, 46 spy on their users’ web-surfing habits. YouPorn, bearing an Alexa ranking of 61, was rated the most egregious offender, followed by YouPornGay.com at No. 8, FuckTube.com at No. 16 and YouPornCocks.com at No. 46. News sites, torrent sites, gaming sites, financial sites, video-on-demand sites and health sites also reside on the list.

“We found that many of these websites make use of a handful of third-party history-sniffing libraries,” the researchers noted. “In particular, of the 46 cases of confirmed sniffing, 22 sites use history-sniffing code from Interclick.com and 14 use history-sniffing code from Meaningtool.com.”

Pitner and Reagan want the court to give the lawsuit class-action status. In addition, court documents indicate the pair seek an immediate injunction barring further spying by YouPorn, plus unspecified damages.

YouPorn has not responded to the lawsuit or to media inquiries.