"This scream actually originates from Shadow Dio's super move 'Charisma' from the game JoJo's Bizarre Adventure. After Shadow Dio screams "WRYYYYYYYYYY", he sends out several sparks toward his opponent. However, due to the popularity of the 4chan flash movie, the fad displays the scream during Dio Brando's super move 'Road Roller', where Dio jumps up in the sky, then lands to the ground on his opponent with a big steamroller. In JoJo's Bizarre Adventure, Dio does NOT use Shadow Dio's scream during this move. "
That saved me some typing.
Basically, you say it when someone gets owned.
You're the guy from that hamburger train, right?