How to do it properly:

Choose a list of victims in advance, and mug each of them once and only once - if and only if you honestly feel that they would pay up if asked. (If you feel they wouldn't, it might be amusing to send them an email describing the chance they missed.) Don't publish the list; each individual mugging must come as a surprise to the muggee. Afterwards the statistics of die rolls will prove or disprove your honesty, and the statistics of responses will prove or disprove the honesty of victims (or maybe your inadequacy as an Omega).