My dad found a phone a few weeks ago and asked me what he should do with it. Knowing how much it hurts to lose personal data, I said I could try to find the owner and send it back.

My first attempt was to search through the files on the SD card in order to find an identifying document (CV, bill, address...) but there were only family pictures.

My second attempt was to unlock the phone and check the information about the owner and the accounts linked to it. But for this to be possible adb has to be enabled. Good thing is that that particular brand shows an option for activating adb on the recovery menu.

But then, it's Android Oreo and I haven't found a way to lift the lock pattern. I thought I could bruteforce it over the shell (as I found there could be about 1300 possibilities for 2 to 5 point patterns), but there is the same attempt throttling as on the screen so that would take ages.

Finally, I found the owner in the most "social" way : The phone was displaying the weather for a particular place. It turns out that there are only 3K inhabitants in that city, si I thought that a big enough Facebook group might help me find the owner. So I posted a message on a 500 people FB group dedicated to this city with a selfie of the owner : someone identified her within 20 minutes.

Mission accomplished 😎

Common Google what is this?