It is very much not anonymized. It is trivially easy (albeit not cheap - around $10k/month) to buy access to mobile ad id data, draw a polygon around your house

It is very much not anonymized. It is trivially easy (albeit not cheap - around $10k/month) to buy access to mobile ad id data, draw a polygon around your house, and get all the “anonymous” ids. From there, you can see all other locations of those ids. When they anonymize you, that just means they give you an is not linked to your phone number or account. It doesn’t mean someone can’t link it for you. The best defense to this is to reset your ad id regularly. Or on iPhones, turn off ad personalization. I don’t know about Android.