With an internal Justice Department document, recently obtained by the Electronic Frontier Foundation (EFF), having revealed that US law enforcement agents have collecting data on social networking sites like Facebook for fighting crime, Internet security professionals have shared their apprehensions with eWEEK.

While the 33-page document underlines the FBI and other police agencies’ authority to use social networking sites for gathering valuable information from as well as about suspects, security experts opine that such ‘undercover’ networking by the federal agents might become an issue for the Justice Department if a line is not drawn between surveillance and privacy.

The document, which chiefly mentions how information can be obtained from the four leading social networking sites - Facebook, Twitter, Myspace, and LinkedIn -, said that the ‘useful evidence’ that can be gathered from these sites mostly includes personal communications and location information; which assist the agents in approving and disproving alibis; and establishing crime or criminal enterprise.

Noting that privacy profiles are an “iffy” issue from the privacy perspective, FishNet’s chief security consultant Shawn Moyer said: “In the case of in real life undercover activity, there are lots of procedural rules around how and when law enforcement performs an impersonation, but for a social network impersonation the barrier of entry is obviously very low, so any agent with a computer and an account could take on a persona.”