It has been asked for quite often but never made the list of features. Now with the Legacy/Current device split there will be a lot more space for Sonos to add options so I’m hoping this one makes the cut soon.

As soon as/if password support is added I predict the forum filling with people who forget their password, and factory resetting everything. I pity the Support folks if this happens.

It seems odd to me, if you’re concerned about people having access to your Sonos to play music, aren’t you more concerned about giving them unfettered access to your computers, and all other devices you have on the network? 

Giving somebody a WiFi password is a million miles away from them having

“unfettered access to your computers, and all other devices you have on the network? “

Why do you think they're the same thing?

Can be, but not guaranteed. 

Ah, so potential unfettered access.

I assume the PIN would just be to add a new device and not to use the App. I'm sure it would be a very welcome addition for many.  Quite strange to not be able to have any control for access to your Sonos syatem. Doesn't affect me but for users where they have to share WiFi but can't split their network or have a guest network or use a travel router (and why should they?), it would be a godsend.

There's already a password required to add a new device. Or are you talking about the controller?