If that speaker is part of a room, it changes the volume of all speakers in that room. 

Note that in the Sonos software, you can turn off those buttons. Although the chances of ‘accidentally’ touching the button on a surround speaker seems really remote, at least for me. That being said, I do have those buttons turned off on all my speakers, I much prefer to use the controller.  YMMV, of course. 

Oh, for what it’s worth, there are no stupid questions, if you don’t ask, you’ll never know ;)

Ahhh thank you kind sir! Much appreciated. I just went into the app and turned off all touch controls. The wife was dusting our furniture while playing some music and she accidentally swiped over the touch controls so I was worried it might’ve thrown the balance all out of wack 🫣 that’s neat they added all speakers to one master volume. 

Edit: Already answered.

Thank you my friend 🫡 much to learn here but glad to be part of such a fine group. It’s been quite the investment but couldn’t be happier with the sound I’m getting out of this system.