Looks like all of those taking shots at Fall Out Boy on message boards may want to think before taking it to Pete in person. A recent incident saw a heckler beaten down by Fall Out Boy's security team.

According to a witness:

A guy started calling Pete a sell-out, asking him 'Where's [girlfriend] Ashlee [Simpson]?' and making fun of his hoodie.

"They did their last song, walked off the stage and headed toward a side door to go out onto the sidewalk. But that's when the scuffle happened. The crowd surged back, then snapped forward. From my vantage point, I could see Fall Out Boy security was pounding on the guy. The guy was down on floor, shirt ripped, bleeding from ear and nose. There was a lot of blood.

Wentz denies that the incident was malicious, claiming self-defence:

The truth is on the way out the door I had to pass directly next to the guy and I knew it, so I kept my head down and walked out. As I did, the guy reached out and grabbed me and said something I couldn't really hear -- it was a glorious use of the English language, though," he continued. "As he grabbed me, I punched him. Yell all you want at me, say whatever, but in a situation like that I will defend myself. After that, of course, it got chaotic, [but] we have several independent witnesses that gave statements saying he grabbed me first … I am not worried over the outcome, as I was clearly in the right. Anything anyone else is saying or writing is simply not true

You can find more on the story right here.