Shadow Profiles is the industry term for the dossiers that Facebook compiles on billions of people, including people who don't have Facebook accounts, merging data from Facebook Like buttons and tracking pixels, outside data brokers, and data entered by Facebook users about their friends, including harvested address-books, tagged photos, and other personal information that can pertain to Facebook users and non-users alike.
Gizmodo's Kashmir Hill continues her excellent investigative work on Facebook's mysterious "People You May Know" system, which has caused consternation among users by making seemingly impossible (and often disturbing) connections, such as "A woman whose father left her family when she was six years old—and saw his then-mistress suggested to her as a Facebook friend 40 years later."
Facebook provides a suite of turnkey app-building tools for Android that are widely used among the most popular Google Play apps, with billions of combined installs; naturally, these tools create incredibly data-hungry defaults in the apps that incorporate them, so that even before you do anything with an app, it has already snaffled up a titanic amount of data, tied it into your Google Ad ID (which is recycled by Facebook to join up data from different sources) and sent it to Facebook.
We're months removed from the Cambridge Analytica scandal and the public outrage of #DeleteFacebook, and new information continues to surface about Facebook's sloppy handling of data and hunger for surveillance. Last month, we learned about an Orwellian patent that might allow Facebook to track you via mobile microphone. Though some have cast doubt on the reports, mobile spyware like the now-infamous Alphonso do track mobile devices via sound emitted by TVs.