The main concern is that technology is allowing police to expend more policing effort than we want them to. Their powers aren't supposed to be perfect, and push

The main concern is that technology is allowing police to expend more policing effort than we want them to. Their powers aren't supposed to be perfect, and pushing their success rate too high is dangerous for society. Exactly. Imagine if we had perfect enforcement of laws against sodomy or miscegenation. In addition to the increase in human misery, it would have been impossible for a reservoir of free personally-invested persons to circulate in society, agitating for change. Manual search forces the police to expend energy enforcing the laws, which forces them to prioritize which laws to expend energy enforcing, which (sometimes, when we're lucky) forces them to be responsive to broader societal values. These databases create a vision of the future which is the very same boot stomping on the very same face in the very same quantity, forever.