I would sit there eating a bagel for the first 4 minutes, starring directly at him. Then I would ask him what kind of music he likes, if he says Pop or Rap, then I will ask him one question about a famous classic rock artist and if he answers incorrectly then...well...I would beat him down and then leave.
As for beating him down.... if you get a chance to (if he doesn't leave after watching you eat a bagel for 4 minutes :P)
I've completely changed my mind about Justin Bieber. If I had 5 minutes with him, I would ask him stuff about Selena, then see if he could get me an autograph from Green Day. I can dream....
I would welcome Justin Bieber into my home with a bow. I would then caress him under the finely-lit living room with candles dotting the sides and corners of the furniture. I would then nestle him in my lap and read him Mother Goose stories, while we discuss the means of changing a 4-wheel drive transmission unit. I would then fry up some sausages and feed them to him while seeing him off in his shiny, black limousine, hoping his free, gratuitous album isn't fake.
ask him for couple of autographs which I would later sell and also ask him to borrow me some money, which I would as you guessed never return, and after that slap him in the face
Remember when Michael Jackson died? Do you know how many of his songs were on the radio? Can you imagine 24/7 Justin Bieber with news reports on him? His songs are RECORDED so it is rather hard to actually stop his music and in the end you'll be punished more than him.
If you think it would be a punishment for him. Go ahead. But who are you punishing? Do you really want him with more publicity than he already has?
_____________________
Answer: If it was just a casual meet thing and you somehow found him it'd be awkward so I couldn't go for the "Become his friend" idea. I guess I'd go for the autographs. $120 a signature. I wouldn't be talking to him if he could sign 50 in the 5 minutes or even just 10.
Despite that I'm guessing that if you did find a way to talk to him it would be from one of those "Meet Justin Bieber" advertisements for him and he'd be scripted and you'd be recorded for live television so it would fail.
To be honest I probably wouldn't want to meet him in the first place.
BOOM, Headshot. Just kidding. I'd probably ignore him. I have no interest in Bieber, although its depressing that some people think his pop fancy stuff is actual music. That is simply my opinion, of course.