This was my thought as well. And I think it is an important fact to keep in mind. You can fool an AI by putting a sticker on a stop sign, but then again you c

This was my thought as well. And I think it is an important fact to keep in mind. You can fool an AI by putting a sticker on a stop sign, but then again you can fool a human by stealing the entire stop sign. Either way you're defacing infrastructure in a way that's potentially dangerous. It's just that the particular failure cases for an AI is different (and somewhat incomprehensible) to humans. Of course, a self driving system could also be linked to a network that has redundant information about the road and could also broadcast its position and immediate intent to all other nearby self driving systems. Now, on the other hand. If a police officer sees a missing stop sign, then it's pretty obvious that there is something that needs to be reported and addressed. However, if there's a small sticker on a stop sign (possibly something even confusable as just dirt or bird poop) then it might not be obvious that this represents a road hazard.