Via The Daily Beast:
A White House national security official was fired last week after being caught as the mystery Tweeter who has been tormenting the foreign policy community with insulting comments and revealing internal Obama administration information for over two years.
Jofi Joseph, a director in the non-proliferation section of the National Security Staff at the White House, has been surreptitiously tweeting under the moniker @natsecwonk, a Twitter feed famous inside Washington policy circles since it began in February, 2011 until it was shut down last week.
Two administration officials confirmed that the mystery tweeter was Joseph, who has also worked at the State Department and on Capitol Hill for Senators Bob Casey (D-PA) and Joe Biden. Until recently, he was part of the administration’s team working on negotiations with Iran.