ORIN KERR: The officer says, I think you’ve crossed the line. I’m going to arrest you. I think you threatened physical force. Therefore, under this law, I’m allowed to do the DNA test. It turns out the officer was wrong, but the DNA test has been conducted and the information has been entered into the database. What then?

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KERR: Traditionally, the Fourth Amendment has allowed the government to follow people in public, to take pictures of people in public, to track them out in the world. And so automated license plate readers and sort of cameras in public that might have facial recognition software attached to them. So far, courts have generally said those are constitutional under the Fourth Amendment.

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KERR: And what courts have suggested is, like, usually, this is not a search, but maybe if there are a lot of cameras and the government can assemble a really careful picture of what someone’s doing with their life at some point, it gets intense enough that it becomes a constitutional search.