Earlier quoted context omitted.
An individual's data sharing with Facebook is less of the issue, here, though. You personally not using it doesn't prevent you from becoming the common thread that ties others together. Just because I'm not on Facebook (I'm not), anyone that's allowed Facebook to see their own contacts, in their phone or email, has shown that they are or are not connected to me in some way. Without me actually ever even having an acc…
That doesn't seem to be very important. It's not the doctor who wants privacy. The people who want privacy allowed Facebook to scrape their contact lists and monitor their locations. They then expected Facebook not to correlate this data with others who contact and visit the same doctor. Why not?
The people who want meat didn't demand tours of the meatpacking factories. They then expected the meat they bought to not be unsanitary and diseased. Why not?