It's not good to get Corey Taylor angry. You may not like him when he's angry.
The lead singer for heavy metal band Slipknot was on-stage during a recent show when he spied a fan busily texting on his cell phone.
Taylor reached out from the stage and, while still singing, smacked the phone out of the man's hand - a moment which was captured on video and posted to the band's official Twitter account.
Phone use during live performances has been a topic of increasing frustration among vocalists and actors. Adele has chided fans during live shows for recording her singing for social media when fans are there seeing her in person, while actress Patti LuPone has gone the route of Taylor and physically removed phones from audience members' hands.
Corey Taylor's abrupt lesson in concert etiquette has been met with debate by fans - some supporting his move, while others have called the artist out for possible damage to property and not knowing the situation in which the fan was using his phone.
"The guy could have been texting about a matter of life and death," tweeted one fan.
"Oh for [expletive] sake," Taylor responded. "If that were the case he WOULD HAVE LEFT."
At any rate, Taylor reported that the fan responded to the incident later with understanding, and that they both shared in a laugh over it.