According to The Register [theregister.co.uk] Microsoft plans to enable their WIFI Sense feature on all versions of Windows 10 by default.
WIFI Sense has been lurking on Windows Phones since version 8.1.
A Windows 10 feature, Wi-Fi Sense, smells like a significant security risk: it shares access to password-protected Wi-Fi networks with the user's contacts. So giving a wireless password to one person grants access to everyone who knows them. That includes their Outlook.com (nee Hotmail) contacts, Skype contacts and, with an opt-in, their Facebook friends.
With every laptop running Windows 10 in the business radiating access, the security risk is significant. A second issue is that by giving Wi-Fi Sense access to your Facebook contacts, you are giving Microsoft a list of your Facebook friends, as well as your wireless passwords.
Microsoft offers a totally ridiculous workaround: you can simply add _optout to the SSID to prevent it from working with WiFi Sense.
Microsoft's page [windowsphone.com] on WIFI Sense hasn't yet made it clear that every Windows 10 computer using WIFI will have the feature on by default. But that page does also include this little gem:
Wi-Fi Sense uses your location to identify open networks near you that it knows about by crowdsourcing.
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Where are the lawyers when you need them?