There's no way prosecutors and courts would actually commit to an Espionage Act conviction of an astronomer for looking at the wrong part of the sky. That's absurd.
Photographing and publishing or sending to unauthorized parties foreign or domestic, bet on it. You might get away with a stern visit from one of the 3-letter-agencies if it's minor importance and ignorance, but do it again...
If you doubt it, please do the test and report back the results.
Of course it is not Soviet Russia, and I'm aware of those activities.
It's one thing for amateurs doing those 'trainspotting' type of activities with commercial- or even professional grade equipment, but another to do it with research-grade telescopes and listening equipment.
Obviously the amateurs are basically unstoppable, and are getting the same level of open information that any foreign agent can get by looking in the open. Nothing new is lost and there is no purpose in chasing the amateurs.
However, we're talking about professional astronomers with both higher-grade knowledge, much higher-grade equipment (and likely operating under at least partial govt funding for the project or equipment), and operating under some regulations and laws. It is silly to expect that being noticed breaking those laws or regs would go un-addressed.
But, as stated above, if you feel differently, feel free to do the actual test and report back your results.
Photographing and publishing or sending to unauthorized parties foreign or domestic, bet on it. You might get away with a stern visit from one of the 3-letter-agencies if it's minor importance and ignorance, but do it again...
If you doubt it, please do the test and report back the results.