San Francisco, March 17 (DPA) US law-enforcement agents are being trained to use social-networking sites like Facebook to befriend suspects and collect evidence, according to documents released by advocacy group The Electronic Frontier Foundation (EFF).

The Justice Department internal training document, called Obtaining and Using Evidence from Social Networking Sites, revealed that undercover agents for the FBI and other agencies set up false profiles on sites like My Space and Facebook to try to nab suspects by getting access to their social networks.

The training manual said that such operations can be useful to communicate with suspects or targets, reveal their personal communications, gain access to non-public information and map social relationships and networks. Information gleaned can also be used to verify alibis and establish locations, the 33-page document revealed.

Social networks are also a good source of information on defence witnesses, the Justice Department's slide presentation said.

'Knowledge is power,' the document said. 'Research all witnesses on social-networking sites.'

The document notes the potential problems with such covert operations with the words: 'If agents violate terms of service, is that 'otherwise illegal activity?'' referring to site policies against establishing accounts with a false identity.

While the Justice Department document left the question open, a document released to EFF by the tax-collecting Internal Revenue Service noted that that IRS employees are prohibited from using deception or fake online accounts to obtain information about taxpayers.

'In civil matters, employees cannot misrepresent their identities, even on the Internet,' the document states. 'You cannot obtain information from websites by registering using fictitious identities.'

The EFF, which advocates for online privacy rights, withheld comment on the Justice Department documents but did praise the IRS policy.

'The IRS should be commended for its detailed training that clearly prohibits employees from using deception or fake social networking accounts to obtain information,' the group said Tuesday.