Description from original post (created 2013-06-16 01:00):
Based off the upcoming movie "The Purge"
Emergency Broadcast System: "This is the Emergency Broadcast System announcing the commencement of the annual purge. At the siren, all emergency services will be suspended for 12 hours. Your government thanks you for your participation." 
https://www.youtube.com/watch?v=Lekx_ZlqyWk Trailer