Responding to myself, in case anyone runs across this. Kerr briefly acknowledges this point in his article against the mosaic theory: The mosaic approach is an

Responding to myself, in case anyone runs across this. Kerr briefly acknowledges this point in his article against the mosaic theory: The mosaic approach is animated by legitimate concerns: it aims to maintain the balance of Fourth Amendment protection as technology changes, a method I have elsewhere called "equilibrium-adjustment." But it aims to achieve this reasonable goal in a peculiar way. By rejecting the building block of the sequential approach, the mosaic theory would be very difficult to administer coherently. Even if courts could develop answers to the many questions the theory raises, doing so would take many years—by which time the technologies regulated by the theory would become obsolete. The mosaic theory would also deter enactment of statutory privacy regulations and force judges to consider questions that they are poorly equipped to answer. If courts must broaden Fourth Amendment rules in response to new technologies, the better approach is to rule that certain steps are always searches. The model should be the Supreme Court's famous decision in Katz v. United States, not the concurring opinions in Jones.