Is this still a problem though? We live in 2014, it’s common place for people to download and re use images uploaded on the internet, whether it be a photo of natural sights, cities, faces of people, or snapshots from tv shows, games, films, books etc. Besides, most of the time, images from films, tv serials, games, books etc don’t hurt the owners significantly. I’ve seen it become a problem only when people take images from news articles, or from websites selling them.
As such, trying to stop people from putting good images simply because someone else owns them will just create more annoyances than anything else. You don’t want to be as restrictive of images as Wikipedia, do you? 