An in-the-closet lesbian mother has sued Netflix for publishing data that she believes could be used to out her.

The unnamed Ohio woman claims her privacy was invaded when the movie rental company disclosed insufficiently anonymous information on the viewing habits of 480,000 customers as part of a $1m contest to improve its recommendation system. By connecting a series of digital dots, it's possible for anyone with access to the data to identify customers by name, giving the more than 50,000 contestants an intimate glimpse into data Netflix promised to keep private, the suit contends.

"Although Netflix touted its privacy protections to induce consumers to become subscribers, Netflix failed to disclose that it would release the movie titles, genres, rental dates, and ratings they assigned to movies, along with other information about their rentals - without consent - as fodder for a contest to improve the predictive value of their recommendation system," according to the complaint, which was filed last week in US District Court in San Jose, California.

The allegations aren't the first time a large internet company has been accused of breaching customer privacy when releasing data it claimed was anonymized. In 2006, AOL released 20 million search queries from 658,000 users. Although the company removed names and other personal information, the disclosure proved to be a debacle after privacy advocates showed the data could still be used to identify the people making the searches.

Anonymized data collected from GPS-enabled devices may not be as anonymous as many expect, either, according to research published earlier this year.

Shortly after Netflix released the data in 2006, researchers from the University of Texas used it to identify several Netflix customers by comparing their anonymized reviews to ones posted on the Internet Movie Database. The researchers also made educated guesses about the customers' politics and sexual orientation. The lawsuit refers to the process as the Brokeback Mountain factor.

The suit, which was filed on behalf of the Ohio mother and several other Netflix customers, alleges the disclosure violates the company's terms of service. Netflix representatives didn't respond to a message requesting comment.

The suit was reported earlier by Wired.com, which has more here. ®