I disagree on that. You have a lot of tolerance for IP violence if you assume that you do not touch the aircraft producers IP-rights because you think that FG aircraft are pieces or art. FG is not a piece of art and your aircrafts are not pieces of art.
Not sure which countries' legislation applies to you, but in many legislations computer games and their artwork are perfectly well recognized as artwork - whatever you personally may think about the matter.
According to your own policy for protecting model meshes, you would have to ask every producer if they have registered a trademark (e.g. for the name of the aircraft) a design right (in Germany) or Industrial Design Right (in many other countries) and whether or not it would be ok to use their product in FG. BEFORE you start working on the model.
No, because such a thing is not necessary when creating artwork and there's no policy for obtaining permission where none is needed (we also don't have a policy for using public domain material - on the grounds that you can use it however you like).
Please stop teaching me about IP-rights and what is right or wrong about it.
Given that you seem in some instances mistaken about how it works, I won't unfortunately stop - not so much because I hope to teach you something (that's really up to you) but rather to avoid other readers of the thread to acquire the same wrong notions you have.
Some people call what you do here "bullying".
Some people call pirating content while shouting 'copyleft' very loudly a perfectly legitimate activity - neither makes it such. Truth isn't decided by what 'some people' say.
I find parts of your stance factually wrong and will continue to (politely) say so. You have certainly given the impression that you want to play down the importance of auditing content for copyright violations - if that is not what you're after, it'd be up to you to state clearly what else it is.
And calling somebody a thief and criminal is TOTALLY different than telling somebody politely that s/he has done something which is not according to YOUR policy.
Please read back - I don't think I called anyone a thief (in the event at hand, unlike others I have not looked at the evidence myself and have not reached a conclusion, so all my comments were of general nature).
More generally though, whether it's okay to call something theft depends on whether something has actually been stolen or not. I see myself under no obligation to be polite to the person who just drove away with my car for instance.
And pirating content (if it happened) would not be just not according to our policy, it would be plain illegal, period (and I do hope your comment is not expressing the notion that you think adhering to copyright is just our policy...)