In GTA Online I was flying around the military base (Fort Zancudo) in a helicopter at night, looking for what vehicles are there. I thought that flying over the base would make me wanted, so I carefully stayed outside. When I spotted fighter jets I decided to risk it and flew over the base, but didn't gain any wanted level! So I flew around for a few minutes, and only got 4-stars when I landed. It was pretty easy to run to the jet, kill a soldier who spawned next to it and fly off.
From what I've read, breaking into the base should be a lot more difficult. Was this just a one-off, or is it easier to break in during the night (or something else)?