Fun fact: it is trivially easy and costs $0 to track an individual through their ad identifier. They’re not supposed to uniquely identify people, but you really just have to drill down like a dozen or so variables and you’ll uniquely identify just about anyone with a smart phone.

Hey, random person for whom this describes, are you

-Aged 30-34 -White -Male -Educated -Spends a lot of time near you work address -Spends a lot of time near you home address -Spends some time where you vacation the exact time you usually vacation there -Is a 49ers fan -Likes artisanal coffee -Android user -Listens to late 90s and early 00s metal -Wears pants size 38/32.

Guess what there’s like 3 of you in the world. And we can get all 3 ad ids in the real time bidding market and track all 3 of you until we deduce which one is you.