As someone who spends a good deal of time in places like the Pentagon, military buildings/bases, and Federal offices in general - the degree to which Fox News dominates every single television is incredible to me. It has to be well over 90% of them outside of the Civilian agencies. It's kind of amazing to be hanging out at the Justice Department and watching a nonstop ticker about how fraudulent and inept the DOJ is. I have a decent amount of friends on the DOD side that legitimately believe Fox News is the only fair and balanced news resource out there, and I'm sure that's in no small part due to it being the default option at every installation they've been stationed.
It'd be interesting to study how those choices get made - I definitely noticed a short-term push towards CNN as a moderate spot between Fox and MSNBC, but there was huge backlash and outcry over CNN being allowed anywhere.