Jofi Joseph, tweeting White House staffer, possibly unmasked by sting, report says

(CBS News) It took the Obama administration more than two years to identify a White House aide who used Twitter to ridicule co-workers and other officials. Foreign policy expert Jofi Joseph was fired last week.

The Obama White House made several attempts to unmask Joseph, including a sting operation. The Washington Post is reporting that co-workers fed him innocuous information to see if it would end up in the musings of @natsecwonk. It's unclear if that led to his capture, but before he became a suspect Joseph was regarded by his colleagues as smart on policy, easy to get along with and nothing like the snarky image that the Twitter posts revealed.

WH staffer unmasked, fired for anonymous, insulting tweets

Joseph really was the "national security wonk" to which his Twitter handle alluded. He was an Iran expert with a master's degree who worked first at the State Department and then at the White House, and he lives in nearby Alexandria, Va. Reporter Michael Crowley knew Joseph as a source. Crowley said of Joseph, "The guy was an expert on nuclear non-proliferation, you know, technical issues like centrifuges and deterrence theory. He knew his stuff, and I respected him for it."

Joseph launched his anonymous Twitter account in 2011. In a statement emailed to Politico, he said it started as a "parody ... (but) developed over time into a series of inappropriate and mean-spirited comments," which were often aimed at political opponents, such as one that said, "So when will someone do us the favor of getting rid of Sarah Palin ... What utter useless garbage."

He also targeted political figures like Ann Romney and Liz Cheney, focusing on their appearance or weight.

His Twitter comments escalated to critiques of the administration's foreign policy and even to his own White House colleagues and bosses, including Deputy National Security Adviser Ben Rhodes. He tweeted, "Poor, poor Ben Rhodes madly spinning away, trying to explain a policy that just makes no sense to anyone, right or left."

Crowley said of the comments, "I am really surprised. I know a lot of people in Washington who are sarcastic, snarky, gossipy who I might have guessed would do a thing like this. Someone like Jofi never would have crossed my mind as a suspect."

White House staffers who are privy to sensitive information are not allowed to use social media from their work computers and phones, CBS News senior White House correspondent Bill Plante reported on "CBS This Morning." In fact, he pointed out, their phones don't even have Internet access - so presumably Joseph had to go out of his way to tweet as much as he did, presumably by stepping outside with his personal phone to report the snarky tweets.

Watch Bill Plante's full report from the White House in the player above