This is the Cato Daily Podcast for Tuesday, August 20th, 2019. I'm

Caleb Brown. An assault in Manhattan. Police got a warrant so

Google would tell them which phones were in the

area. Is it overstepping? Is it an appropriate use of tech to solve crimes?

Cato's Julian Sanchez comments.

As you understand it, this is a Manhattan District Attorney

getting a warrant for Google phone data

and using that essentially to generate a list of suspects.

That's right. And in this particular case, from what we know publicly about the

precise methods that were followed, there are actually reasons to not be as concerned about it as one might otherwise be.

The concern is, you know, it's not clear that this is the process that's always followed as this technique

is used and this has become increasingly popular with local law enforcement.

We don't have a lot of aggregate data about how much it's used by different

agencies and what the rules that are in place are.

It seems like in this case, to the extent that there are rules enforced that would limit or, you know, assuage certain civil liberties concern,

there are really rules imposed by Google and not by, you know,

local or certainly federal law. So this is really in a sense a descendant of a technique that had been known as

tower dumps dating back to at least 2010.

The first case I'm aware of what was used was in Texas involving a group of bank robbers called the Scarecrow Bandits because they were known for showing up to robberies and kind of ratty gear in big hats.

And at the time the technique was called a tower dump because the idea was instead of going to a platform like Google, they would go to sell providers and say we want essentially all the phones that connected in this window of time to the closest

cell phone tower.

And that would give you usually a pretty big number of people in the area and you could compare a bunch of different tower locations

...