Best answer by Ryan S
In case anyone finds this thread with a search, we've published an announcement on the topic here. This is the result of a prank, made possible by misconfigured networks.
To make sure you're not vulnerable, we encourage all Sonos users to follow best practices for securing home networks and to turn on automatic updates. Best practices include securing home networks with unique passwords on routers and wireless networks, turning on firewalls, and ensuring caution when making internal devices publicly available, such as through port forwarding or another protocol.