A (semi) real-world application of the is-a-person technology was suggested to me a year ago by someone whom I think is now a list member. To protect his privacy I will change the story slightly. He wanted to set up an online game which would be ongoing for some time, and which new people could join periodically. New members would be given a certain amount of resources (fuel, money, etc.) to start with, and then they would compete with others in the game to try to get more. At any given time standings would be available to show who had done the best in terms of getting the most resources. The problem was that based on the rules of the game it was hard to prevent people from colluding to transfer resources among themselves. This would allow someone who was doing poorly to create a bunch of pseudonymous accounts, enter them in the game as new users, and then to transfer their initial resources to his main account. The result would be that the standings would reflect skill at creating pseudonyms more than the abilities which the game was supposed to test. He asked whether there would be some way to ensure that only one account per person was playing the game. Basically, he was asking for an "is-a-person" credential. One solution would simply be to get a name, address, and phone number from each participant, but he didn't want to violate his players' privacy to that extent. Without an infrastructure supporting this kind of credential, he decided not to go ahead with his plans for the game. This is too bad because the game was actually going to test some very interesting economic and political theories and it would have been good to see it in action. Hal