Of all the objections I've seen people raise to automated vehicles, this is one of the most ridiculous. What stops such a robbery now? Is there some spate of truck drivers running down would-be thieves that I have literally never heard about?
This was actually a plot point in a little-known B-grade sci-fi movie called "Solar Crisis". There were stretches of highway far from cities with very little traffic aside from the occasional robotic cargo truck, which were implied to have been programmed to stop if any living thing were encountered blocking the road. Gangs of robbers would steal cargo from trucks in isolated areas by tying a cow to a stake in the middle of the road, causing the robotic truck would come to a stop in front of the cow while playing a recorded voice that shouted to "clear the highway". There is a scene where some characters are riding in the back of one of these automated cargo trucks and then have to escape some of these robbers.
The implication is that if some of our roads gradually become devoid of humans, robbing automated vehicles will become a "thing". It doesn't actually sound that far fetched, really. It would presumably be safer for the crooks than robbing a real truck today for three reasons: 1) they wouldn't have to threaten a human (thus lowering the stakes if they get caught), 2) the trucks likely would not be built to shoot back (think of the potential liability for the trucking company if it were), 3) the trucking companies would likely not put much energy into pursuing the criminals, so long as the losses were small in the grand scheme of things.
It's similar to the notion of people shooting down delivery drones and stealing the packages. People will do it, and it will likely be tolerated to some small degree. Even today we already have people stealing packages off doorsteps, although there is occasionally vigilante justice in those cases:
I imagine as soon as it encounters such a situation it'll start streaming video of what's going on over a wireless network and then someone can report this. You don't need a human to be an in-person witness to record the crime.
