also, would using a MVNO carrier prevent the tier-one carrier from having access to location data? either technically or legally? i.e. is it even possible for an MVNO to position themselves as "the carrier that doesn't do this kind of shady stuff"?
MVNOs can't really provide any protection. Google is "demanding" that their tier-one carriers don't sell their MVNO customers' data, but just by throwing their weight around. i doubt they'll continue after this blows over, and other MVNOs don't have that kind of weight.
which means every single mobile customer in the US has to choose the least shady infrastructure owner -- between ATT, Sprint, TMobile, or Verizon. those are literally the only four options in terms of which company you want to trust with a never-ending stream of your personal location data. and if you use an MVNO, chances are good that _more than one_ of these companies has access to your data.
