Elena Kagan

Google handed police the robbery case in three escalating tranches: first 19 anonymous accounts within 150 meters of the bank, then nine, then the names behind three. One was Okello Chatrie, later sentenced to 12 years. The Court ruled that pulling location data this way triggers Fourth Amendment scrutiny.

But it declined to call geofencing itself unconstitutional, remanding the probable-cause question to the lower court. As one reader put it, the celebration is for a rubber stamp with a few extra steps.