I’ve written before about the “Mosaic Theory” some courts have recently employed to conclude that certain forms of government surveillance may trigger Fourth Amendment protection in the aggregate, even if the surveillance can be broken down into components that don’t fall under the traditional definition of a Fourth Amendment “search.” This has been applied specifically to high‐tech forms of location tracking, where several judges have concluded that a person may have a privacy interest in the totality of their public movements over a long period of time, even though observing a person at any particular public place in a specific instance is not an intrusion on privacy. I’ve explained in that previous post why I find this reasoning compelling. Legal scholar Orin Kerr, however, remains unmoved, and suggests that divergent decisions applying the Mosaic Theory to government acquisition of stored cell phone location records effectively serve as a reductio of that theory:
Read the rest of this post →To my mind, this opinion reveals the absurdity of Maynard’s mosaic theory. The analysis is all “look ma, no hands.” No one knows where the line is, or even what the line is. Sure, you could just count days of surveillance: perhaps 30 days triggers a warrant but 29 days doesn’t. But there is no reason the access to records has to be continuous. The government can skip around days, or get records from a few days here and a few days there. Who can tell how much is enough? No one knows what is revealing, because what is revealing depends on what the records actually say — and no one but the phone companies know what they say. So Judge Orenstein has to wing it, announcing that “he cannot assume” that the information would be revealing because it has breaks in time. But it’s not clear to me why the break in time matters: It’s the same net amount of data collected, so I don’t know why it matters if it was collected all at once or over several discrete periods. And how much of a break matters? If 21 days is too long, is 21 days with a one‐day break enough? How about a 3‑day break? One week? No one knows, it seems, not even the judge himself. [.…]
There are some readers who will say that the cause of justice sometimes requires hard decisions, and that if judges need to make arbitrary calls like that, then that is what we pay them to do in order to enforce the Constitution. But as I see it, the oddity of the inquiries called for by the Maynard mosaic theory shows why it is not part of the Constitution at all. In Fourth Amendment law, the lawfulness of government conduct has always been viewed discretely: Each government act is either a search or it is not a search. Under Maynard, conduct can be a non‐search if viewed in isolation but a search if viewed in context — but there is no guide to tell how much context is proper. If you want to say that certain conduct is a search, then just be direct and say it’s a search. That’s fine. But a mosaic theory, in which non‐searches become searches if grouped a particular way, has no proper place in Fourth Amendment law.