How to find a lost phone with dead battery, using Google Location History Takeout

post by Wei_Dai · 2019-05-30T04:56:28.666Z · score: 51 (22 votes) · LW · GW · 3 comments

Or, wow, it's crazy how much Google knows about me.

(I'm writing this in part because I tried to Google variations of "how to find a lost phone with dead battery" and among all the articles in the search results that I clicked on, didn't see anyone write up this technique that I later figured out myself.)

I lost a brand new Android phone recently inside my own home. I knew it was inside my home because I remembered using it after I got home. Normally in that situation I would call it or use Google's Find Device feature to make the phone ring, but the phone's battery had died before I realized that it was lost. I spent a couple of hours looking for it in all the obvious places, like behind sofa cushions, in the garbage can, everywhere in the house I had been (or might have been but forgot) since I last used the phone, but failed to find it. Find Device gives the last known location of a phone, but the error circle encompassed the whole house so that wasn't very helpful.

Eventually I decided to download all of the data Google has on the history of the phone's location using a feature called Takeout, just in case it offered any further clues, and that's when I realized that in Google's databases there's an entry for every time one of my phones moves even a little bit, with a timestamp, location estimate, velocity estimate, and a guess of whether I was walking, running, biking, in a car, etc. (presumably inferred using the phone's accelerometer). I converted the data from JSON to CSV and then looked at the last time the phone moved. (BTW the timestamps are in UTC time, which confused me for a while until I realized that.) Then I looked at my Google Activity History to find out what I was doing at that time. The Activity History told me I did a particular Google search around that time, and I remembered I was sitting in a particular armchair while doing that search. (Google Activity History also has a whole bunch of other information, like every time I launch an app on my phone, or visit a website using Chrome.)

Of course I had searched that armchair already but this knowledge incentivized me to do a much more thorough search, and it turned out that the phone had fallen down a very narrow crack in the armchair to a pocket underneath. I ended up retrieving the phone by cutting open the fabric covering the bottom of the armchair.

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comment by Qiaochu_Yuan · 2019-05-30T22:11:05.551Z · score: 30 (13 votes) · LW · GW

Google Activity History is sort of terrifying but also great. I used it when someone stole my laptop to learn that the thief had googled pawn shops in the area; I contacted one of the pawn shops they looked up and a bit later they called me telling me someone had brought in a laptop matching my description. They lied to her and told her they needed to process the laptop for a few hours and she needed to come back, and in that time the police were called, she was arrested, and I got my laptop back the same day it was stolen.

comment by Wei_Dai · 2019-05-31T06:04:06.918Z · score: 9 (5 votes) · LW · GW

Google could have saved me a lot of time (not to mention helped a lot of people find their phones) if it had implemented this in Find Device, and displayed something like, "The last time your phone moved was X, and you were doing Y around that time." I wonder if nobody at Google thought of it, or if it was deemed too likely to creep out Google users.

comment by shminux · 2019-05-30T06:57:31.323Z · score: 2 (1 votes) · LW · GW

Interesting, didn't know of the Takeout feature and of the Activity History, both appear quite useful, thanks!

Basically Google services are becoming closer and closer to unlimited eidetic memory, and hopefully some day the brain/machine interface will feel as seamless as the brain-eye interface.