It’s totally rational to worry that your phone is tracking everything you do.
If you’ve set up a new mobile phone recently, you were likely prompted with an innocent-sounding request for your “usage information.” The phone probably assured you that it would collect your data “anonymously,” and that it would send the information back to the carrier or phone manufacturer to “improve your service.” In theory, this sounds reasonable. If your phone keeps dropping calls when you’re at work, wouldn’t you want it to report back its troubles? If all your coworkers’ phones also drop calls, maybe the carrier will notice that it has a dark spot in its network and try to fix the problem. For just this reason, I’ve always opted in to my phone’s diagnostic monitoring—I consider it a kind of civic duty, like calling the fire department if you see a cat stuck in a tree (though you’re not actually supposed to do that, turns out).
The problem with diagnostic monitoring, though, is that phone companies don’t say how they do it. What kind of information can they collect from your phone? How often? What do they do to ensure that the data isn’t personally identifiable? Over the last few weeks we got some answers to these questions. They’re not pretty.