LarrylLix said:
Continue to read more sites. There is a ot of BS out there.
OK, here's an interesting one from Network World, a reasonably respectable source, and the title speaks for itself but it is an interesting read:
http://www.networkworld.com/article/2956393/windows/microsoft-windows-10-wi-fi-sense-an-astoundingly-bad-idea.html
Notably in it is the statement that it is turned on by default if you use Express Settings, though you also have to say it is OK to share with your friends, at which point apparently it uses Outlook.Com, Skype, and Facebook (you choose). But you can NOT determine which of your individual contacts can share, so if you let Bob in and he's in your Outlook.Com contacts, and Joe is there also, he's golden. So make sure only your trustworthy friends are in your contacts!
Here's the word directly from Microsoft:
http://windows.microsoft.com/en-us/windows-10/wi-fi-sense-faq
An interesting aspect of this is that apparently it can work by accident for you. Say you have a network and are happily running Windows 8 or XP or something, and have nothing to do with Windows 10 and never heard of WiFi Sense. You know, like 80% of people. Your friend Mary comes over, and you share your password with Mary, as you always have. Now if Mary is running Windows 10 and is the sharing type, then Mary's friends can use your network as well. This kind of accidental sharing by the uninformed is probably more of a concern for corporate or other institutional users. Microsoft's answer is change your SSID to include _optout, which of course presumes you even knew you opted in by, well, just existing.
The core issue is that Microsoft designs for user convenience and features first, and security is somewhere in the also ran. They have improved dramatically over recent years in some regards, but they continue to make default behavior risky, rather than making people CHOOSE risky behavior. Because, frankly, most people prefer that.