Theyve been doing this for over a decade.
Twitter, Facebook/Instagram, Xfinity/Comcast, AT&T, TMobile, Verizon, CVS, Walgreens, and grocer Pharmacies etc all have sold aggregate data that can be cross referenced to identify individuals under the guise of terrorist tracking and accomplices 

 Facebook was started to gather data on college students and we all rushed to sign up when it came out because we wanted to talk to our friends online.

I feel had. 

 Facebook was in part successful because people didnt want to pay a subscription fee for classmates dot com