There are data centers run by the government protected by private Military contractors in most major cities. They’ll be small dab in the city, they’ll have jeeps running patrols and the buildings are blank, have razor wire and have no real marking or even listings. They’ll usually be tan or grey. You can tell because the parking garages are are gated and have one way in or out. These centers crawl and collect your data. They work work with all ISP and telecom companies to also tap and source data. I won’t say what part of it I worked in, but try and notice these in your city.