I think it would require someone to fly a spy sat up near one of the SpaceX sats. From the ground the atmosphere would attenuate the signal too badly and you'd only have visibility for a few minutes at a time as it passes overhead maybe.
In practical terms I don't think it's a major concern. Much more likely that the spy agencies would tap the lines coming out of the ground stations.
> Much more likely that the spy agencies would tap the lines coming out of the ground stations
Which is a significant step backwards for e.g. Russia.
Currently, all data between Asia and North America runs on cables. Anybody can spy on those. If those data did satellite laser hops, only those with ground stations would have access. Everyone else gets locked out.
The company I work for changed its internal routing of data to use encryption for 100% of traffic crossing the public internet. I have to think everyone else is doing this as well. Is spying on cables like this even useful? How would ay usable data be extracted?
In practical terms I don't think it's a major concern. Much more likely that the spy agencies would tap the lines coming out of the ground stations.