Y'see theres a point there. If someone posts up stuff without asking we might have used art within the map and got permission to use it as long as we only posted it up here. That's particularly true for commissions where the person who paid for the map has an interest in keeping hold of it. So the fact is that *we* might get into hot water over it too and I think that's probably the crux of the problem. That sounds like a contrived example but recently I found out that the textures I have been using cannot be used in a CC work so suddenly some of my maps cannot be CC any more and therefore shouldn't be re-posted. So we don't want to be sued either.

Reality is, nobody is suing anybody though TSR who used to make D&D before Wizards / Hasbro used to be known as "They Sue Regularly".