I hear this a lot and its utter nonsense.
You carry a phone right now with a GPS tracker in it and the mobile signal is triangulated. They know where you are right now.
Every time you use a smartphone app, that data is recorded in that app and the integration with Google, Apple and FB means they already have this data to know your movements. Usage, location, advertising, metrics.
Wear a smart watch that gathers health data (Fitbit for example), that data is tied into your personal record with the above, building up a more complete picture of you.
The only difference is that this data now is gathered by private entities, not the government, yet they seem to get a free pass. Now imagine your unique national insurance number and your NHS medical record being tied to that data from those private entities. Bang, a complete user profile in the hands of for profit enterprises. Is that more or less acceptable than 'big gubberment' holding all the data. BG by the way, already hold a lot of data, look at the government gateway ID where you can link medical, passport and driving licence into a single record.
Don't use a spurious argument about future data analysis, when its already a mature industry more than a decade old.