A quick use of it's search facility online will produce ample questions and answers on the subject over the past year or so. The Home Office has theft problems, so does the DWP, and HMRC has lost 44 laptops in the last twelve months. The only reason this has suddenly become an issue for the media is because of 'Discgate' but it should have been an issue much earlier.
Theft and loss of Government computer equipment is endemic across the board. What might have been on stolen equipment is completely unknown, but hey, it might be nothing right?