luup.call_action("urn:micasaverde-com:serviceId:Sonos1", "Say",
                 {Text="You idiots. You broke into the wrong house – prepare to get messed up. Yes you, you broke into the wrong house and you're about to get all messed up.", Language="en", GroupZones="ALL",
                  Volume=80, SameVolumeForAll="true"},

Hoping it doesn't get used, but smiling more than a little while testing it out to make sure it work.
#homeautomation   #sonos