People could also be tricked by specifically designed stickers as well.
This organization designed a sticker that is designed to scare people into stopping their car. http://news.blogs.cnn.com/2010/09/09/3d-illusion-in-street-t... https://www.youtube.com/watch?v=8r26AwT7PTM
While people would get angry at being tricked and would put pressure on the city to remove the adversarial sticker, self-driving cars not have the sympathy of the public.