I sold my Play5 a while ago, and it was reset twice, but somehow is still connected to my Spotify account. I am constantly fighting for control over my account with some stranger. Judging by this person's musical taste, it appears appears be a teenage girl! One moment I'm chilling to some Elbow, when the next, I'm being ear raped by Witney Houston!
As stated, the Play5 has been reset, and i have also forced logout of all devices in my Spotify account, and I have changed my Spotify password. Unfortunately this hasn't helped. What is also interesting is that when this other person plays Spotify, it shows up as the name that I gave to my old Play5 speaker "Kitchen"; could be a coincidence, but I somehow doubt it.
Is there some way that you can break this connection in the Sonos 'back end' systems?