According to TMZ Glenn Danzig headlocked a fan who didn’t respect
the “no photos, no videos” restriction at his show. Navid Farsi was taking pictures with his cell phone during Danzig’s show and when the singer realized snatched it from him. After the show Farsi met Danzig at his tourbus and he was filming with a camera, which led to a headlock with the singer saying that he was an asshole.
Farsi has a history in such incidents as he was arrested in May for throwing powder sugar in the face of Maroon 5 singer, Adam Levine, while he was walking on stage for Jimmy Kimmel’s show. Also, in 2012 Danzig was held back by security before attacking 4 photographers at Bonnaroo Festival who were taking photos of his show despite the restriction.
https://www.youtube.com/watch?v=VtkfdlcLPK4
