Of course that still fails with someone who has too much time on his hands and a bunch of proxies.

I guess the question is not if anyone will ever go to that extreme but how often? Will it be a rampant problem or will most people not even care to even go to those lengths?

No system is perfect; there's a limit to how much I can prevent lameness in an anonymous environment.

I feel that the only way to properly judge the effectiveness of the concept is to actually try it out.