I'm no expert on copyrights and legal mumbo jumbo, but we're not also talking about copyrights, we're talking about trademarks too... like in the case of new york city's skylines with named buildings:
http://www.photosecrets.com/photogra...and-trademarks
there are actually rules to follow about using photos or likeness to them in any process that involves making money.
Disney may not come after you for creating a likeness of tron, but the minute you start charging for it, they'll be on your ass faster than a smart kid on a fattie... or is that a fat kid on a smartie?
Now I do know of a story about disney going after a little kid who drew a likeness of one of their characters... sued the family in some preposterous lawsuit. So cybergun "protecting" their "clients'" intellectual interests is not so far fetched as long as there's money and a lawyer involved.
As for how TM, CA, KS and KA can make their p90s without being hassled, I don't know. Maybe it has something to do with how the GBB version might operate close enough to the real thing that they could be infringing more on just copyrights and trademarks... maybe getting into patents as well which I think deal more in the functionality of something?