Microsoft is offering most Windows 7 and Windows 8 users a free upgrade to the software giants latest operating system Windows 10. Windows 10 will by default prompt to you share access to WiFi networks to which you connect with any contacts you may have listed in Outlook and Skype and, with an opt-in, your Facebook friends. The feature, which Microsoft has dubbed Wi-Fi Sense, doesnt share your WiFi network password per se it shares an encrypted version of that password.”]
Source: https://krebsonsecurity.com/2015/07/windows-10-shares-your-wi-fi-with-contacts/