ermmm.... as someone who deals with actors every day, I can tell you that this is not fake.... Those a real emotions... it's not that 99% of you find it not scary that nobody will....
The thing you see isn't acted... you can even see that by their other body language...
Also, if it was fake: Then they are the best young actors I have EVER seen. Although, if it was faked, then why do they look sometimes for an instant to the camera? If they can act that good, then surely they can surpress the urge to look directly into the camera.... So again, conclussion, not fake...
It can be a "setup" though, and proberly is: They obviously know about the cam (they look at it several times)... but why wouldn't you record it? People do silly stuff all the time (like recording how one jumps out of a window)...
Also, it is quite possible that their parents or sister or whatever said to them: "You should see yourself, just rediculus"
two guys: "no we are not"
parents: "yes you are... lets record yourself, when you play"
two guys: "we don't believe you, we are normal....
"
parents: "so, we can record it?"
two guys: "pfff, sure"
And how it got on the net? Well everybody knows how "safe" things on the computer are when you have a "good friend" or a "sister" which has access to the pc....
In short: I work in the theater bussiness and believe me, those are real emotions, that isn't faked...
Edit: OMG... I just analyzed a totaly rediculus video
..... I need a life....