Disable WiFi Sense and never allow apps to store passwords! With "Wi-Fi Sense" enabled, users share Wi-Fi network, access including
the encrypted password, with their Facebook, Skype, and Outlook contacts. To disable this, clear all the boxes at Start > Settings > Network & Internet > Manage Wi-Fi Settings (or Wi-Fi > Network
Settings > Manage Wi-Fi Settings).
Check out this link for other Windows 10 privacy issues you may want to avoid.