Facebook last week amended a lawsuit it filed in June against 10 unknown individuals and 10 unknown companies for unlawfully accessing its servers.

Based on information subpoenaed from Look Communications and Rogers Communications, two Canadian ISPS, Facebook on December 12 amended its complaint to name three individuals and three companies among the defendants.

The social networking site's legal filing names Brian Fabian, Josh Raskin, and Ming Wu, as well as 1564476 Ontario Limited, Istra Holdings Inc., and SlickCash as defendants. Several remaining defendants have yet to be identified.

Slickcash is a sex site that's associated with 1564476 Ontario Limited and Istra Holdings.

"Slickcash.com is a top 1,000 site that reaches over 2.7 million U.S. monthly uniques," says Internet metrics company Quantcast in its summary of the Slickcash site. The adult-oriented site "caters to a fairly wealthy, primarily male crowd" and that "[t]he typical visitor reads nature.org and shops on usedcarsale.com." (Quantcast offers no further information about the intriguing association it proposes between interest in porn, ecology, and pre-owned cars.)

Facebook alleges that during the 15 day period between June 1, 2007 and June 15, 2007, the defendants tried to access information on Facebook's servers over 200,000 times using "an automated script that attempted to harvest information from other Facebook users."

The alleged information harvesting effort cost Facebook over $5,000, the legal filing claims, noting that the data accessed includes user names, passwords, network affiliations and e-mail addresses.

"We do not have any details to share at this time, and we do not comment on pending litigation," a Facebook spokesperson said via e-mail.

Concerns about illegal information harvesting at Facebook appear to be ongoing. "Facebook has been and continues to be harmed by these unlawful attempts to access Facebook's proprietary computer system," one of the legal filings states.

Cyber security experts have been warning since at least last year that social networking sites will be increasingly targeted by cyber criminals for the wealth of personal information they possess.

In a related story, the Pew Internet & American Life Project on Monday released a survey that finds most U.S. adults online to be relatively unconcerned about the accessibility of their personal information online.