"When you visit a site or app that uses our services, we receive information even if you’re logged out or don’t have a Facebook account. This is because other apps and sites don’t know who is using Facebook.Hard Questions: What Data Does Facebook Collect When I’m Not Using Facebook, and Why? | Facebook Newsroom
Many companies offer these types of services and, like Facebook, they also get information from the apps and sites that use them. Twitter, Pinterest and LinkedIn all have similar Like and Share buttons to help people share things on their services. Google has a popular analytics service. And Amazon, Google and Twitter all offer login features. These companies — and many others — also offer advertising services. In fact, most websites and apps send the same information to multiple companies each time you visit them."
Tuesday, April 17, 2018
Hard Questions: What Data Does Facebook Collect When I’m Not Using Facebook, and Why? | Facebook Newsroom
Oh, so nothing to worry about, then?... Check the full post for details