Kansas City, MO (KCTV) -- It's the concert tirade that's made national headlines.

Staind frontman Aaron Lewis interrupted his own performance on Saturday to reprimand a group of fans who crossed the line with an adolescent girl.

During the band's appearance at the Kansas City Rockfest, some rockers near the stage hoisted a young girl into the air to crowd surf. Lewis finished his verse, but didn't even warn his band before he launched into a profanity-laden rant.

"Listen up you (expletives) ,that (expletive) girl right there is like 15 (expletive) years old and you (expletive) pieces of (expletive) are molesting her while she's on the (expletive) crowd," he ranted. "Your (expletive) mothers should be ashamed of themselves."

The rant lasted for an entire minute. View the video here (NOTE: clip contains strong language).

Music blogger Cassiopia Demers witnessed it from just a few rows back. Demers, who is known as KC Cassie, said it was clear that the crowd was groping and pinching the teen, and that the girl wanted to be put down.

"I think she was a little bit uncomfortable because she didn't really know what was going on," she said.

Lewis told the group that they should be beaten, and threatened to stop the show again if they continued. He told them if they continued to bother the girl he would single them out, and tell the rest of the crowd to beat them.

The crowd cheered throughout the entire indignant interlude, and clapped again when Lewis finished his song and told girls they were safe to crowd surf once again.

Allen Roach, another music blogger, also witnessed the rant. He said he respects Lewis for standing up for the young girl.

"It shows a lot of character. And I think the fans will see that," he said. "We're starting to see these things as being frowned upon."

The Kansas City Police Department is aware of the reported molestation, but the girl or her family have not come forward to file a police report. Police said they are interested in investigating the incident.

Thank God he did not actually single someone out for an ass-beating. I'm sure that would have landed him in prison.