FBI agents may impersonate journalists while conducting undercover investigations, and an agent who posed as an editor with the Associated Press during a 2007 investigation did not violate agency policies, the Department of Justice Office of the Inspector General found in a report released Thursday.

The conclusion sparked consternation across social media by journalists, civil rights groups and some legal experts, who have argued that the practice – by its very existence – threatens to heighten public mistrust of reporters, damage journalists' credibility and have a chilling effect on sources and whistleblowers who may fear that their contacts in the media are actually undercover agents.

"The Associated Press is deeply disappointed by the Inspector General's findings, which effectively condone the FBI's impersonation of an AP journalist in 2007," Associated Press Vice President Paul Colford said in a statement. "Such action compromises the ability of a free press to gather the news safely and effectively and raises serious constitutional concerns."