My Sonos is logged into Spotify with my own creds. So if I'm driving around using Spotify and my wife fires up the Sonos with my creds saved to it, it stops playing in my car.

She's got her own account on our family plan, but she's not going to change the username/password to hers every time she uses the Sonos (and me do the reverse).

I suppose I could generate a "dummy" family member account used just for the Sonos, but then it wouldn't have my playlists....