EFF has posted documents shedding light on how law enforcement agencies use social networking sites to gather information in investigations. The records, obtained from the Internal Revenue Service and Department of Justice Criminal Division, are the first in a series of documents that will be released through a Freedom of Information Act (FOIA) case that EFF filed with the help of the UC Berkeley Samuelson Clinic.

One of the most interesting files is a 2009 training course that describes how IRS employees may use various Internet tools -- including social networking sites and Google Street View -- to investigate taxpayers.

The IRS should be commended for its detailed training that clearly prohibits employees from using deception or fake social networking accounts to obtain information. Its policies generally limit employees to using publicly available information. The good example set by the IRS is in stark contrast to the U.S. Marshalls and the Bureau of Alcohol, Tobacco, Firearms and Explosives. Neither organization found any documents on social networking sites in response to EFF's request suggesting they do not have any written policies or restrictions upon the use of these websites.

The documents released by the IRS also include excerpts from the Internal Revenue Manual explaining that employees aren't allowed to use government computers to access social networking sites for personal communication, and cautioning them to be careful to avoid any appearance that they're speaking on behalf of the IRS when making personal use of social media.

The Justice Department released a presentation entitled "Obtaining and Using Evidence from Social Networking Sites." The slides, which were prepared by two lawyers from the agency's Computer Crime and Intellectual Property Section, detail several social media companies' data retention practices and responses to law enforcement requests. The presentation notes that Facebook was "often cooperative with emergency requests" while complaining about Twitter's short data retention policies and refusal to preserve data without legal process. The presentation also touches on use of social media for undercover operations.

Over the next few months, EFF will be getting more documents from several law enforcement and intelligence agencies concerning their use of social networking sites for investigative purposes. We'll post those files here as they arrive.