> who have real-time data on where every connected phone is all the time
Not really. They know which mast it's connected to and can do signal strength triangulation. Their location info is a lot less good than what the device makers with wifi map data can give you, hence why every so often we get a news story about how Uber knows where you are a lot better than a 911 operator does.
I would be more concerned about ATT/Verizon/T-Mobile, who have real-time data on where every connected phone is all the time and a FISA court can always serve them with a secret warrant.
Also, what you are describing is not Dunkin paying Apple for an advertisement. If it is, then it would be huge news that Apple is pushing non Apple ads to its devices.