Driverless Cars and Location Privacy, Part I

One of the coolest developments in technology today is the advanced development of driverless cars. Sounds a touch Marty McFlyish (though it's certainly no flying car), but it's a lot closer to reality than you may realize.  The California legislature has passed a law allowing the cars to be driven on California state freeways.  According to Google, these cars are now significantly safer than their human counterparts.

I'm all for it. But there is one legal issue that would be wonderful to address before the movement goes mainstream.

These cars function by using satellite and network data to navigate roads -- essentially a more complex and developed GPS system. This means they can be tracked. And anything that can be broadly tracked is a handy tool for law enforcement officials to follow individuals whom they suspect might be up to no good. In the non-virtual world, there's a Constitution (specifically, the Fourth Amendment) that safeguards individuals from warrantless searches and seizures. In the virtual world, um, not so clear.

Driverless cars make those two worlds, ahem, collide.

Federal judges, old farts that they tend to be, typically find it challenging to grapple with the workings of the internets and newfangled technology. Cellular network tracking data can reveal a detailed picture of your life. It tells where you are, what you want to know, and what you do. And that can make things easy for police looking for hints on where to find you when you're doing bad stuff.

To give one example, imagine if police requested all the data of bar patrons from 10 pm to 2 am throughout a city, and could then track those patrons' movements home. Driverless cars makes this easy. That sure would be an efficient way of cracking down on DUIs. But so would waiting outside a bar and giving everyone who left a breathalyzer. The latter is illegal. At this stage, it isn't perfectly clear that the former isn't.

The underlying legal question is whether a law enforcement official, by requesting location tracking data, is conducting a "warrantless search" under the Fourth Amendment.

The simple answer is, we don't know yet.