Here is an article about the Department of Energy opting for thin clients to prevent security incidents by limiting local computing functionality.  You may have heard of the incident in the UK late last year where Her Majesty’s Revenue and Customs lost the records of 25M taxpayers.  The government’s initial response in that case was to disallow workers from transporting data outside of the office, which is about as realistic as outlawing porn from the Net.  Users have come to expect a rich Internet experience, and compromising this risks the ability to keep talented employees.  It is a tough but solvable problem, we need to make sure we are building in all the user-centric functional requirements into our cloud computing.