I don't use their apps. They are almost certainly sharing data behind the scenes, they openly say this in op's link about how WhatsApp uses your data: > impro

I don't use their apps. They are almost certainly sharing data behind the scenes, they openly say this in op's link about how WhatsApp uses your data: > improving their services and your experiences using them, such as making suggestions for you (for example, of friends or group connections, or of interesting content), (...) across the Facebook Company Products; There is a small chance that they've gotten all my data from the people at the other side of the conversation if they have the fb app installed I guess, which really isn't much better.