The F.B.I. used...

... counterterrorism agents to investigate the Occupy Wall Street Movement, according to an article in the New York Times. 

From the piece (my emphasis): 

...F.B.I. personnel around the country were routinely involved in exchanging information about the movement with businesses, local law-enforcement agencies and universities. 

An October 2011 memo from the bureau’s Jacksonville, Fla., field office was titled Domain Program Management Domestic Terrorist. 

The memo said agents discussed “past and upcoming meetings” of the movement, and its spread. It said agents should contact Occupy Wall Street activists to ascertain whether people who attended their events had “violent tendencies.” 

The F.B.I. was concerned that the movement would provide “an outlet for a lone offender exploiting the movement for reasons associated with general government dissatisfaction.” 

No mention was made in the article about F.B.I. infiltration of the tea party movement.