Facebook can have your data even if you're not on Facebook-
“One of the creepiest things brought to light during Mark Zuckerberg’s testimony on Capitol Hill this week was how Facebook can amass data to construct what are being referred to as “shadow profiles” of you, even if you’ve never opted in or joined the world’s largest social network.”
“Facebook may be using the data it collects from people not on the service for reasons it considers totally benign. And it may not use the data at all. But the suggestion is also that Facebook may not be great at protecting your information — a concern amplified by the social network's disclosure that 87 million Facebook users' information was improperly shared with political targeting firm Cambridge Analytica.
Facebook’s sheer size and reach across international borders only heightens the potential risk, even for those who have steered clear of the service.”
“Some lesser-known ways Facebook has devised to track its 2.2 billion users:
Facebook tracks when you need to recharge your phone and even knows when you're looking at the Facebook page on your computer screen.
Collects a lot of data about the various devices people use to log into Facebook, such as computers, their smartphones and their tablets. >Facebook collects information how much available storage they have and the strength of the Wi-Fi signal the machine is receiving.
The company also knows whether you're actually looking at your Facebook window or if you've just got it open as one of many tabs. >Facebook can gather information about nearby devices or other devices on the user's network.”https://www.usatoday.com/story/tech/news/2018/06/11/what-facebook-ceo-zuckerberg-told-congress-massive-data-dump/692936002/
But let’s not limit ourselves to Facebook. Search:
“how your every move can be tracked digitally”
One miscellaneous tidbit:
Facebook’s voting process is rigged from the inside. While non-insider shareholders receive just one vote per share, Zuckerberg’s inside circle is entitled to 10 votes a share.