Research:
Some Android apps send Facebook your data without consenthttps://mashable.com/article/facebook-data-sharing-apps-privacy/?utm_cid=hp-r-1#7sYOKAK0OPqw
QuoteSome apps go even further, sending data to Facebook that Privacy International describes as "incredibly detailed and sometimes sensitive." One example is travel search app Kayak, which sends Facebook detailed information about users' flight searches, including data like departure/arrival date, city and airport as well as number and class of tickets.
Worth a read.