Violence erupted at star-studded, free Altamont Rock Festival Subscribe for more Breaking News: http://smarturl.it/AssociatedPress Website: https://apnews.com Twitter: https://twitter.com/AP Facebook: https://facebook.com/APNews Google+: https://plus.google.com/115892241801867723374 Instagram: https://www.instagram.com/APNews/ You can license this story …