This is not fake*
http://www.heaviermetal.net/2016/02/07/metallica-removed-from-super-bowl-50-coldplay/Tempers flared behind the scenes at Super Bowl 50 at Levi’s Stadium. A security team escorted members of Metallica from the backstage area just before the halftime show was slated to begin.
Apparently, there was some sort of a mix up as to whether or not Metallica was scheduled to make an appearance during the halftime show. Hundreds of thousands of fans signed a petition asking the NFL to consider letting Metallica perform. Ultimately, the NFL decided to ignore their requests.
James Hetfield and Coldplay’s Chris Martin reportedly got into a heated exchange after Martin accused James Hetfield of eating all of his celery sticks, which were provided by event staff catering. Insiders say the two almost became involved in a physical altercation.
Metallica drummer Lars Ulrich could be heard shouting “you stole our halftime show you son of a bitch!” before attempting to shove one of his drum sticks in Chris Martin’s ear.
* it's fake