I have never heard of this (outside of adult sexual practices) and it disturbs me greatly. Has anyone else heard of this phenomenon?
Christ, do we have to have a talk with children about every possible dangerous behavior these days? I hate to say it but if they weren't so young I'd be nominating these youngsters for the Darwin Awards... (Sorry, but it's true.)
http://www.cnn.com/2005/US/07/13/choking.game.ap/index.html