Some fans have a tendency to go off the rails when they have a chance to see artists perform live, but you have to draw the line somewhere -- or else there will be consequences.

One fan learned that the hard way when J. Cole was in San Diego for his Forest Hills Drive tour, when they decided to throw an iPhone at him. Another fan caught it all on video.

First of all, why on earth would you throw a cell phone at someone? Not only are they insanely expensive, they're also dangerous, especially when you're aiming directly at the face.

But somehow Cole played it cool. He stopped for a few seconds after the initial impact -- right in the nose? -- and then he simply decided to pocket the phone and continue rapping.

Hopefully that phone was unlocked, and after the show he decided to tweet and Instagram a few things from that person's account to embarrass them. Seems like reasonable punishment for making a very bad decision.