Prior to the change in late 2001, government employees could earn miles, but could only use them to upgrade to business (not first class) or use them for other government flights -- some agencies have "gainsharing" programs where if you save the government money, you can get an "award" generally equal to 50% of the savings. For a couple of years before 2001, the Comptroller General (among others) was lobbying to remove the restrictions because of a desire to make government employment more attractive. Prior to the change, a few government employees were actually disciplined for using miles for vacation trips.