Is it just me?

Do you ever see cars where the back seat windows are covered in stickers? I can just picture the children sitting in the back peeling their little stickers from their sheets and then happily sticking them to the window. See, if that happened in my car, it would be without my permission and my kids would be giggling thinking they got away with something. Is it just me that feels like this practice is insane??? Am I too controlling? Am I a bad mom because I don't allow my children to stick SpongeBob and Hello Kitty stickers all over the windows? Should I do it? Will it make my kids happier and more well-adjusted? I've got to know. Next time I see one of those cars, I think I'll stop the driver and ask!