Just so everyone else is clear, fedrooms.com is a website developed by GSA to make booking hotels for federal government employees on TDY easier. The rates on this website may sometimes be different from the "government rate" offered on an individual hotel brand's website (which sometimes actually exceed per diem rates).

When fedrooms.com first started years ago, I believe it did state something that it was for official travel only. However, now it does state:

Customer base
FedRooms was designed for all federal employees, military and civilian. The FedRooms rate can also be used by government contractors and state employees on official travel and federal travelers on leisure travel, if the individual hotel agrees.

http://www.gsa.gov/portal/content/105404

It is true that for certain government rates, such as airlines and the official tdy rental car rate (the one that includes insurance, not the leisure rate), you can get in trouble for using it, so I'm not sure why some on the forum are bashing others for wanting proof that you can use it vs believing what some random person on the internet says.