"Facebook uses an internal database to track rivals... The database stems from Facebook's 2013 acquisition of a Tel Aviv-based startup, Onavo, which had built an app that secures users' privacy by routing their traffic through private servers. The app gives Facebook an unusually detailed look at what users collectively do on their phones..." - More Privacy Concerns

Wait!.. you mean an app(like facebook) where users voluntarily enter the intimate details of their personal lives doesn't respect their privacy? Sorry for the bias folks, but facebook users typically don't respect even their own privacy.