Yes this is true of major ad networks, but there is also straight data brokers who "just" buy/sell data. FB and google used to (idk about now, don't care to ch

Yes this is true of major ad networks, but there is also straight data brokers who "just" buy/sell data. FB and google used to (idk about now, don't care to check) allow you to upload data you gathered/bought and use it for tracking. To prove a point, i created a fb ad to target my parents and family (uploaded their email, phone number, identifiers, interests, locations they frequent - only data i knew fb already had) and watched as their ads became "hey vineyardmike's parents. the internet is not private".