Bypassing spying, geofencing and other regulatory stuff, perhaps? Also curious what the can of worms might be.

All countries have strict regulations on radio waves, whether that's sending or receiving. The UK for example requires a license for base stations that stipulates things like geographical boundaries, etc.

You can't freely blast radio waves into a country without falling subject to its varying regulations, but the regulations for "pre Starlink" satellite broadband/phones/etc are fairly well established.