A Consumer Reports study involving 709 volunteers: a total of 186,892 companies shared the volunteers’ data with Facebook, averaging 2,230 companies per person (Jon Keegan/The Markup)

Jon Keegan / The Markup:
A Consumer Reports study involving 709 volunteers: a total of 186,892 companies shared the volunteers' data with Facebook, averaging 2,230 companies per person  —  A new study looks at who is sending information about your online activity to Facebook … By now most internet users know their online activity is constantly tracked.