James O'Keefe, the conservative activist who has used heavily edited video stings to embarrass ACORN, NPR, and, less successfully, Sen. Mary Landrieu, is on the ground at Occupy Wall Street.

O'Keefe was spotted and photographed this afternoon in New York City, looking banker-ish among the crowd that's gathered there to protest bankers and their friends in government. Gawker re-posted the photo from Twitter with a warning: "Watch out for this man." They've also got video of O'Keefe, just strolling around, though he's said to be "scheming."

There was instant speculation about O'Keefe's plans on Twitter, including suggestions from some of his detractors that leaving New Jersey to attend the protest might be a violation of the three-year probation period to which he was sentenced after attempting a sting at Landrieu's office. (He and three accomplices entered Landrieu's office dressed as telephone company workers, hoping to catch her staff on camera refusing to answer phone calls from constituents upset about health care reform.)

But while O'Keefe has been restricted from out-of-state travel on occasion, he has been permitted to leave New Jersey multiple times, including for paid speaking engagements and personal trips, the Associated Press reported.

So, the guy who's famous for secretly videotaping liberals to try to embarrass them went down to the liberal Wall Street protest, where he was immediately recognized and then followed around being videotaped, presumably by a liberal. Got it.

For a good run-down of the past exploits of O'Keefe, here's Zev Chafets' profile from The New York Times in July.

Update: We have a call in to Ryan Girdusky, who handles press inquiries for O'Keefe at Project Veritas, for an answer to that question about probation and travel restrictions. (Girdusky returned our voicemail message, but got off the phone saying he had "another call" when asked about probation.)

Gawker now says the most recent motion in O'Keefe's court case asked for out-of-state travel only through Sept. 30.