The stickers could even mess with the speed-limit recognition systems already available on some production cars. University of Washington researchers say the trick isn’t foolproof, though.

A team of researchers says stickers on street signs could be enough to confuse self-driving cars. Amid the rush to develop self-driving cars, there are a few questions that need answering.

Researchers at University of Washington, University of Michigan, Stony Brook University, and UC Berkeley have figured out how to hack self-driving cars by putting stickers on street signs.

If attackers know how a car classifies the objects it sees (such as target photos of signs), they can generate stickers that can trick the car into believing a sign really means something else.

Street art — namely, spray-painted graffiti on building walls, train cars and traffic signs — has been a popular, often rebellious, DIY tradition in urban centers since the 1960s.