Once again I have my views on that. UP and BNSF have both been known to come down quite heavily on commercial people cashing in on their corporate trademarks, and so they should. many years ago, Auran was criticised for not supplying UP stuff with Trainz. They actually did a pilgrimage to the US of A to sort that one out and nearly fell on their feet as a result. (See another post of mine somewhere else in these forums a day or so ago.)
The question is, could they (UP et al) ever be bothered chasing after a 14 year old with an eye for creating great content? I doubt it very much! Auran probably has a duty of care in allowing the stuff to be placed on the DLS however. In many cases, it's akin to piracy and they would be seen to be supporting it in the same way as the P2P search engines.
What you do outside Auran is actually none of their business, so if you wish to use the stuff privately, or even share it with your friends, that's your balminess, and your business alone. If UP bothers to contact you, the best you'll ever get will be a letter asking you to desist. The operative word there being "asking:"
Every enterprise wants to promote their products and corporate image whenever they can. KFC will never challenge privateers (no pirateers) who use their branding in a responsible way. If you want to do it commercially, that's another story. Always use corporate branding in a way that promotes the company and they'll love you forever. Degrade them and expect a nasty response. Degrading can be a simple thing like showing signage with some of the words blacked out, or even graffiti on the walls.
Just ask yourself this very simple question and answer it like a responsible adult: "Would I be offended by this if it was my company?" If the answer is "No", then you're relatively safe.
To repeat myself for the millionth time. Stop worrying, build whatever you want and enjoy doing it. Just don't expect Auran to accept it on the DLS because it may be legally or plainly unethical.
