During his monologue, Leno featured a mock Facebook page for suspect Faisal Shahzad.
While making a joke about Shahzad's "Activities" section of the profile, it was visible — though neither mentioned nor highlighted — that "Team Coco" was one of his member pages. (TheDailyWh.at was the first to point it out).
NBC and O'Brien's reps refused to comment, while Leno's rep deferred to the network's response.
Besides getting criticism for also trying to mine humor from a fresh and potentially deadly incident in the monologue, Leno has been getting mocked for recycling or outright repeating jokes at last weekend's White House Correspondents' Association dinner.
A video put together by politico.com juxtaposes him telling jokes on his show and again in Washington.