TBH: I download only stuff from the Web which is labeled CC0 to be shure. But at the end how would i know if something is stolen or not, i can not go through the web and search for similar stuff that may had been created by someone else and verify it. This would take days and weeks and at the end i still wouldnt know if its stolen or not.
I come from the music business and there its been you could call it a tradition taking sound samples from other artists for decades for creating new things. As long only short parts are taken noone would ever complain and go after it. Not shure how its treated in this type of business. Would picking the exact colour of an armor already voilate something, or must it be a texture ? Ok i dont want to raise a discussion about this. Just want to say that its almost impossible to verify things already in lack of knowledge who may have possibly been a creator of something i have downloaded somewhere. Sometimes its obvoius though.