[This article](Windows 10 privacy problems: Here’s how bad they are, and how to plug them.) has a solid, I think, description of the privacy issues with Windows 10 - real and potential - and, more importantly, how to escape the defaults and set it up to protect yourself.
Nice. Bookmarking for when I update.
Pretty much every service you use, including apps, email providers, and OS track and monitor everything you do. Even FaceBook is notorious for breaking their own TOS regarding privacy. Read the fine details in any agreement and you will understand that nothing is private anymore. What I am getting at is whether you let windows10 track what you do to improve your experience or not, your information is out there somewhere.