Maybe at first, but go ahead and test your theory. We’ll just stay here on the roof to see if you break your leg by jumping off, metaphorically speaking.
I’m sure you can walk up to any fence around a military installation and take a picture but if the MP’s see you, you will be stopped. At air shows, all of the sensitive stuff will have been secured or transported off the base to prevent any errant shutters.
As far as an airport, being they are now considered security zones, the observance of one snapping pictures from an obscure location like the corner of a parking garage at obviously secure things like surveillance camera locations will incite the response noted in the article. To prove their point, all it takes is to review the cameras contents as the days of film are virtually gone. The proof will be in the pudding.
No issues in the airport or on the jet.
IF you hide the camera or go poking around in places not in plain view, that is another story, as that behavior reflects nefarious purposes and that is the difference.