The notion that mass warrantless ALPR surveillance is fine because “ALPRs can see only a fraction of the roads in a given jurisdiction,” should not fool anybody. Nobody who opposes this kind of mass surveillance is concerned about the percentage of pure roads ALPRs photograph. Our concern is rather that roads are integrated and indispensable travel networks. So if cameras capture a person at points A, B, C, ad infinitum, the government can learn a lot more about him than the mere fact that he was on a few isolated patches of road at a few isolated point in time. That is not an incidental feature of these ALPR systems—it is an essential part of how the major players pitch their own products to the government: Hey look, we can create maps of where drivers have been! We can find out who drivers associate with! We can learn where they commonly visit! It’s hard to take seriously a defense of mass warrantless ALPR surveillance that won’t even acknowledge what the cameras are designed to do in the real world.