I'm pretty excited whenever a legal case comes up that includes a police tactic dramatized in The Wire, but that's not why I'm interested in this one. This is a rare Fourth Amendment case when I think it should be a fairly easy case and the government should win.
Now, Eugene Volokh sees the issue differently, and when Volokh isn't talking about economics or public policy in general, I tend to think he's a pretty sharp commentator. I think we should take his initial reaction seriously:
But the installing of the device may give a Justice Scalia or Thomas second thoughts; the act of installing the device is the act of interfering with someone’s private property, and it likely would be a taking under Fifth Amendment principles. Given the historical connection between the Fourth Amendment and trespass law, it’s conceivable that an originalist Justice might conclude that the interference with a person’s private property without a warrant triggered by installing the device violates the Fourth Amendment even if the subsequent use does not.I admittedly am not terribly strong on recent Takings doctrine, but the general background here is that the field of Fifth Amendment protection of personal property has been aimed squarely at environmental law. The typical Takings case involves a legislative effort to dictate the actions of private land holders, who find relief through the court by showing that the legislation has degraded their economic prospects. A development company can no longer build an assisted-living community in a swamp--now a 'wetland;' a lumber company cannot cut down trees on their own property in which endangered species roost; etc... If the Fifth Amendment has anything to say about installing a device on the undercarriage of a car or in the hollow of its bumper, it would have to take value away from the car. The only limitation that the GPS tracker removes from the vehicle is that it becomes less valuable for the commission of crimes. Perhaps if the GPS trackers were a preexisting network that the police could tap into at will, then there would be serious 4th Amendment concerns. That access would require a warrant. Because the police have to specifically pick a target and have hands-on access to the vehicle, it makes the technology less dangerous to general abuse.