You’re not supposed to but that doesn’t mean you will not to. I guess it all depends on the prank you’re setting up and the person you’re choosing to punk. If it was anybody else but Zach Braff this probably wouldn’t even happened.
Ashton Kutcher and Donald Faison set up, what they thought to be “the perfect” prank for Zach. They hired some kids to cover Zach’s new Porsche with spray paint. So Zach and Donald go to a liquor store, they get outside and see these kids spray painting his new car. Zach freaks out and starts running after the kids. Things got wrong when he caught one of them and started beating the hell out of him.
"They choreographed the whole thing and I wasn't supposed to catch the kid, but I caught him… and I'm not a big fighter or anything, but, with the adrenaline and everything, I just started pummeling him. I didn't know and it was so dark… (but) part of the punking was that it was, like, a 12-year-old. It turns out it was fake spray paint. They edited (the fight) out, because apparently you're not supposed to punch people on 'Punk'd.'"
Yes you’re not supposed to, but that doesn’t mean you will not to.