Why would the list be false, better yet, how could the list be false? The sheer number of the names and the fact that they're all actual characters means that it's not just a bunch of random names thrown together to make a fake list; there's also no reason why he'd make a list of random people and claim they're hackers when it'd be so easy to prove they never even existed. The fact that there are several known, or highly suspected hackers on the list only adds to it's credibility. While it's still entirely possible that it's totally fake, the likelihood of it being fake is almost non-existent.
About the only question to credibility I could think of would be do you have to use your real in-game name to register for it, or could you write down anything? Although that argument loses most of it's strength since you'd only do that if you think that your actions are going to be publicized in any way, so I highly doubt the list isn't real.