How not to get caught in law-enforcement geofence requests

This article has been indexed from Errata Security

I thought I’d write up a response to this question from well-known 4th Amendment and CFAA lawyer Orin Kerr:

Question for tech people related to “geofence” warrants served on Google: How easy is it for a cell phone user, either of an Android or an iPhone, to stop Google from generating the detailed location info needed to be responsive to a geofence warrant? What do you need to do?

— Orin Kerr (@OrinKerr) September 15, 2021

(FWIW, I’m seeking info from people who actually know the answer based on their expertise, not from those who are just guessing, or are who are now googling around to figure out what the answer may be,)

— Orin Kerr (@OrinKerr) September 15, 2021

First, let me address the second part of his tweet, whether I’m technically qualified to answer this. I’m not sure, I have only 80% confidence that I am. Hence, I’m writing this answer as blogpost hoping people will correct me if I’m wrong.

There is a simple answer and it’s this: just disable “Location” tracking in the settings on the phone. Both iPhone and Android have a one-click button to tap that disables everything.

The trick is knowing which thing to disable. On the iPhone it’s called “Location Services”. On the Android, it’s simply called “Location”.