To clarify for anyone wondering, 404 Media and WIRED have a partnership so WIRED will occasionally publish their content and they hope to collaborate together on articles (although I'm not sure if this was one of them)
Mobile devices are pretty good at protecting location privacy these days: Android at least puts up a fuss if something wants location data. Are they also tracking via IP geolocation and ad surveillance?
Proximity lets you infer lots of things.
If you have location over time, you can learn a lot about where a person spends their time which lets you infer what they like to do which advertisers will pay a premium for.
I haven't been in the industry for the better part of a decade but at least back then it was possible to see which grocery store(s) you went to versus drove past using the location data.
Through other means, we could obtain your receipt / purchase data (never use PII when signing up for a discount program!)
Now I know you're willing to drive past the cheap store to buy expensive produce at the bougie grocery store.
If you're a high end retailer and your market is "affluent, healthy people", you're going to pay for a list of people that demonstrate some sort of preference for expensive, healthy things.
Or, if my sales team is paying attention to what the data teams are finding, they'll get the cheaper grocery store to buy your info, too. "Hey, you're already driving past, here is $discount to come shop here instead..."
Spend a lot of time at bars? Cool. We have people that want to buy your contact details. Most of those bars are queer friendly? Cool, we have a different bucket to sort you into and a different set of marketers that'll buy contact info from that bucket.
You can learn a TON about a person from where they do (or, do not!) spend their time but in the real world and online.
Candy Crush, Tinder, MyFitnessPal: See the Apps Hijacked to Spy on Your Location - https://news.ycombinator.com/item?id=42651115 - Jan 2025