If you put it out there, then you really only have yourself to blame. Yes, its frustrating when you put so much effort into creating something and someone steals your idea and claims it as their own, but quite frankly you knew that when posting it. Anyone posting anything on the internet, IMO, cannot be upset when someone steals it, you put it out there knowing that someone can, and most likely will, take your work. I'm a writer, but I don't put my work on the internet for people to read and steal, and the same should be true for your sim creations. If you don't want it taken, don't upload it to an online gallery.
