I took all kinds of pictures when I was overseas in the Navy ('70-'73), never a problem, aircraft, missiles,
flight line, on missions, foreign country's, foreign airbases.
Then when I came back and landed at San Diego, not only was I excited to be back, but all those boats really got the juices going, I was an Airedale ( Aviation mechanic, not on a boat). I got stopped, I got searched, they took all my camera stuff ( old school SLR long lens etc.), well the guy on the radio wanted to know what ships (boats in AV speak) I was taking pictures of, a quick look around, I picked out the most innocuous ships I could find, cargo types, tugs, The guy on the radio ( I'm guessing some Navy security kind of guy) told the civilian rent a cop to give me back my cameras and stuff and let me go.
That was the only time I can remember anyone asking me what I was doing.