Crew leave China's space station for Earth after 90 days

If you abandon a ship at sea = derelict and anyone can grab it. How does this work with water borne survey drones and bouys etc.? It makes sense that these are operating known objects, how are property rights respected with these objects?

How does it work with space stations, satellites etc? The current problem with large numbers of satellite parts, tanks, collision crap - are they free for people to de-orbit for the good of man? Currently few objects have enough salvage value to make deorbiting removal worthwhile? Can the launcher be assessed a salvage fee to cover the cost? I know new stuff usually has de-orbit mechanisms in place, but there are many old bits of satellite debris making some orbits dangerous? https://en.wikipedia.org/wiki/Kessler_syndrome

some countries take the 'fuck you - get off with it approach'