Wired has the article All the Ways Facebook Tracks You—and How to Limit It.
If you have a Facebook account—and even if you don’t—the company is going to collect data about you. But you can at least control how it gets used.
I still use Facebook to advertise posts that are on this blog, but for those who don’t have a real need for Facebook, they might rethink what they are doing. Be aware that
Facebook owns WhatsApp and Instagram, too,