A GAME! Can you figure out what happened?

Look at this:

http://utoronto.facebook.com/profile.php?id=28101218

then this:

http://utoronto.facebook.com/profile.php?id=28101108

and this:

http://yorku.facebook.com/profile.php?id=48900038

and finally, this (at the wall):

http://nyu.facebook.com/profile.php?id=802182

Can you piece the story together? Serious points to you if you can.