A new Windows 10 feature called WiFi Sense is intended to make it easy to join nearby wireless networks by automatically connecting you to free wi-fi hotspots.

It can also connect you to friends’ security-protected wi-fi networks without the need to manually type in their security key.

How do you control it?

WiFi Sense shares your network security key with people in your contacts list. No one ever sees your actual password – an encrypted version is shared invisibly in the background when a contact’s Windows 10 PC is within range of your network.

In real-world terms, the dangers are fairly small. But you can’t choose which contacts to share with – it’s all or none.

You can disable the feature by searching wifi in the Windows Start search bar then clicking. Change WiFi settings.

If you allow someone with a Windows 10 device to join your wi-fi network in the traditional way (by letting them manually enter your security key), they may inadvertently share access to your wi-fi with their own contacts via WiFi Sense.

Currently, there’s no setting in Windows 10 to address this. One workaround involves changing your wi-fi network name (SSID) by adding the suffix ‘_optout’ to the end of your current SSID – this tells Windows 10 devices not to store or share your security key.

Or, you could refuse wi-fi access to anyone with a Windows 10 PC until Microsoft adds further controls.