I think maybe 6-8, not sure. I was going to go further but the site went down too quickly. Users were selected based on having a large number of posts.

I wanted something to make it sound realistic. And rationalist/EA culture loves surveys and collecting data. :)

To add some missing context to this:
-I'm part of the EA community and have been for several years. To the extent that you need a community member to blame for this, it is me. When doing this, I was operating under the belief that the community would be judging me personally, which is why I openly admitted to doing this on Facebook.

-I would have known about Petrov Day anyway regardless of Chris' message.

-Phishing attacks can often have in excess of 80% success rate. If you had received this, you would have likely entered the codes as well, even though everyone thinks that they wouldn't. Which is just one of the reasons why it doesn't make sense to punish recipients for making this kind of mistake.

-The campaign wasn't targeted at Chris, it was sent to lots of users. Retrospectively, I should have excluded Chris from the list of users. (I really regret not doing this, and I would like to apologise to Chris for this.)

Thanks, I'm glad to hear that. :) Also, very thankful that the LW community took this really well.

Beyond that, as for my motivations, aside from curiosity as to whether it would work, etc. I considered that it would be an interesting learning opportunity for the community as well. With actual nukes, random untrusted people also have a part to play. Selecting a small group of people tasked with trying to bring down the site might even be a good addition to future instances of Petrov Day.

For what it's worth, I took care to ensure that the damage from taking the site down would not be too great. The site was archived elsewhere, and the admins themselves accepted the risk of the site going down by starting this game. If this could have hurt people, I wouldn't have done it.

Beyond that, loyalty and trust are also very important to me. If the admins had trusted me with the launch codes, I wouldn't have nuked the site (intentionally).

After thinking more about this experiment, it has got me thinking about the payoff matrices. Is there anyone that would have pressed the button if there was guaranteed anonymity, and thus no personal cost? If so, make a second account - I'd be curious to hear your reasoning. Also, in this case there is no tangible benefit that anyone could get by nuking the site. How do we adapt this to situations where there is a benefit that can be gained by pressing the button?

P.S.: My offer still holds! Admins, if you're feeling adventurous, give me the codes next year and I'll prove that I won't use them!