Hi,

My name is Omega. You may have heard of me.

Anyway, I have just tossed a fair coin, and given that the coin came up tails, I'm gonna have to ask each of you to give me $100. Whatever you do in this situation, nothing else will happen differently in reality as a result. Naturally you don't want to give up your $100. But see, if the coin came up heads instead of tails, I'd have given you each $10000, but only to those that would agree to give me $100 if the coin came up tails.