I fear that this may be only the first time that we hear of this… a physical hack to speed limit signs that could change the speeds of self-driving cars. I shudder to think of the various malcontents or evil doers, and what they might come up with in a world which is automated, and not governed by common sense.
A single piece of electrical tape stuck to a 35mph (56kph) road sign is enough to trick the autopilot software in Tesla’s vehicles into speeding up to 85mph (136kph).

The vulnerability was reported by McAfee Labs, the security research arm of McAfee, on Wednesday. Steve Povolny, head of McAfee Advanced Threat Research, and Shivangee Trivedi, a data scientist working on the same team, discovered the attack when they probed the camera system aboard Tesla’s Model X and Model S vehicles, both built in 2016.