Hi ,
When Wi-Fi Sense is fully enabled, it shares most of your Wi-Fi access passwords with all of your Outlook.com, Skype, and Facebook contacts. According to Microsoft, it says that Wi-Fi Sense only shares your passwords with direct friends/contacts, and not friends-of-friends. Wi-Fi Sense automatically connects you to nearby Wi-Fi networks, helping you save your cellular data for when you really need it and giving you more Internet connectivity options. Wi-Fi Sense can do a lot of things for you to get you connected to the Internet using Wi-Fi, so you don't have to do them on your own. These include:
- Automatically connecting you to crowd sourced open Wi-Fi networks it knows about.
- Accepting a Wi-Fi network's terms of use on your behalf and providing additional info for you to networks that require it.
- Letting you exchange password-protected Wi-Fi network access with your contacts to give and get Internet access without seeing each other's Wi-Fi network passwords.
If you don't want to use Wi-Fi Sense, you can disable the Wi-Fi sense in the settings. If you want to disable Wi-Fi Sense, hit the Start button and type "Wi-Fi", and then click "Change Wi-Fi settings". In the settings applet that pops up, click "Manage Wi-Fi settings". From there, you can see different settings, there you can turn Wi-Fi Sense off. You can disable password sharing with Facebook, Outlook, or Skype; and at the bottom there is a list of your known Wi-Fi networks, where you can opt in and out of password sharing.
I suggest you to refer the below article for more information about Windows 10.
http://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/frequently-asked-questions-windows-10/5c0b9368-a9e8-4238-b1e4-45f4b7ed2fb9