Scanning someone's ship should probably be illegal. If I were him, my immediate assumption would be they've pirates and set up an ambush for cargo.
Or... They are scanning the new ship to determine if
it is a pirate ship. If simply scanning a ship was illegal, then there would be vastly more "shoot first" scenarios, as that would be the only way to determine the intention of the other ship.
Without being able to scan the ship for, say, ID and, by extension, allegiance you would have no way to determine if they were, for example, pirates.
What they are doing constitutes harassment, but only to the point of someone today videoing or taking pictures of another's car/truck, which certainly isn't illegal (at least not on public property, which is basically any paved road, except driveways, which aren't roads).
Now, if their scanning goes so far as to read their cargo? That could potentially be illegal. But getting the architecture of the ship and module/weapon information, not so much. Understanding the combat capabilities of those around you, in situations like this, is more of a safety precaution than a sign of aggression. And disallowing that would put everyone at risk.
Again, harassment, due to the number of people doing it and the (implied) length of time they are doing it for. But it's clearly stated that his ship is unique in this universe, and that the people doing it are engineers curious about this unique ship that has shown up in their work area. It would be like saying someone can shoot another for asking (far) too many questions about their modified car.
Not a perfect analogy since the
only real world equivalent is the picture/video one, and then Google-ing what was captured.
Ok. Enough wall of text.