An interesting new feature within Windows 10 lets users share passwords for Wi-Fi connections with each other, automatically, through some server-side magic and, hopefully, a robust form of encryption.
The idea behind Wi-Fi Sense is to let friends connect to the routers of friends without the modern inconvenience of having to actually ask for the password (and signify that checking your phone is more interesting than their company), a feature it presumably activates by storing your Wi-Fi password on its server somewhere in some cloud farm. It's been part of Windows Phone 8.1 for some time, but its appearance in Windows 10 should open it up to the mass market, as laptops galore offer to share their owners' connections with everyone they know.
The key worry is Microsoft's explanation that it works by: "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," meaning that all those other people you know with Windows 10 devices have the option of auto-connecting to your home network's internet connection.
It's not just a Microsoft suite initiative either, as the service's FAQ nothes that it can: "Let you exchange Wi-Fi network access with your Facebook friends, Outlook.com contacts, or Skype contacts to give and get Internet access without seeing each other's Wi-Fi network passwords."
Meaning Microsoft's building the mother of all Wi-Fi password databases, although it's for its eyes only, as it attempts to calm security conscious users by explaining: "...the password is sent over an encrypted connection and stored in an encrypted file on a Microsoft server, and then sent over a secure connection to your contacts' phone if they use Wi-Fi Sense and they're in range of the Wi-Fi network you shared. Your contacts don't get to see your password, and you don't get to see theirs."