FBI overstepped terror link probes after 9/11
The report said the FBI improperly used the cover of "terrorism" to investigate a number of domestic activist groups from 2001 to 2006 including Greenpeace, People for the Ethical Treatment of Animals and the pacifist Thomas Merton Center.
The Justice Department inspector general's report, requested by Congress four years ago, said the FBI classified these investigations as "domestic terrorism cases" but had little to back this up.
It said this was based on "potential crimes" including trespassing and vandalism "that could alternatively have been classified differently."
The report also said the FBI "made false and misleading statements to Congress" about the investigations including surveillance of an anti-war rally, and said that the agency should review whether "administrative or other action is warranted" for this.
The inspector general concluded that these were a number of specific cases rather than a bureau-wide policy.
"The evidence did not indicate that the FBI targeted any of the groups for investigation on the basis of their First Amendment activities" or expressed political beliefs, the report said.
"We concluded that in several cases, the FBI predication was factually weak and in several cases, there was little indication of any possible federal crime as opposed to local crime."
It said that the FBI went to observe a 2002 protest by the Merton Center, a group based in Pittsburgh, Pennsylvania that says it is dedicated to peace and social justice.
"We found no evidence that the assignment was made pursuant to a particular investigation or in response to any information suggesting that any particular terrorism subject might be present at the rally," the inspector general stated.
"The FBI stated in a press response and (FBI) Director (Robert) Mueller stated in congressional testimony that the FBI's surveillance at the event was based on specific information from an ongoing investigation and conducted to identify a particular individual. These statements were not true."
The American Civil Liberties Union said the report showed the FBI "improperly spied on American activists involved in First Amendment-protected activities and mischaracterized nonviolent civil disobedience as terrorism."
ACLU policy counsel Michael German said the FBI "has a long history of abusing its national security surveillance powers, reaching back to the smear campaign waged by the American government against Dr Martin Luther King."
He added that "we are all in danger of being spied on and added to terrorist watch lists for doing nothing more than attending a rally or holding up a sign."
FBI spokesman Paul Bresson said however that the lengthy review "did not uncover even a single instance where the FBI targeted any group or any individual based on the exercise of a First Amendment right."
Bresson added that the report "disagreed with a handful of the FBI's investigative determinations over the course of six years, (but) it has not recommended any significant modifications to the FBI's authority to investigate criminal conduct or national security threats."