This game has been all over the media lately. Basically a group of low life punks target someone and one person attempts to knock out the victim with one punch.
Here is a video:
Here is a blog post by a Budo Taijutsu practitioner named Don Roley covering his thoughts on the Knockout Game. This is a very good blog post on how to avoid being sucker punched.
http://www.coloradospringsninjutsu.com/Blog/Entries/2013/12/3_The_Knock_Out_Game.html
