krebsonsecurity[.]com/2024/10/the-global-surveillance-free-for-all-in-mobile-ad-data/?ref=404media.co
This is a bit of a long read... TLDR; every Android phone has an Advertising ID, unless you turn it off / delete it. When you visit a web page for example, the site's backend will send out a request for bids to show you ads. To get higher bids, that request will provide a wealth of data about you, including your exact current location. These streams of data requesting bids are open for most anyone to read, and data brokers gobble them up. And because they record all of the locations you visit, these data brokers can sell access that allows their clients to put together a fairly accurate profile of whomever they wish.
