Vash, what the hell are you talking about? Where does Rait come into all of this?
@Pong, he refers to Rait, who probably has the best win-loss ratio of any other player here. It's actually frustrating how good he is. =D
I have no idea how common multiple accounts are, because I simply do not come across them. I currently seem to be playing only these "Mastermind" games, and I'm fairly sure that none of them have multiple accounts, and are all individual persons. Before that, when the site was younger, I do not recall nearly as much of this cheating, and if multiple accounts were ever used, they were used poorly, because it did not stop me from winning a decent amount of games.
There are a few complaints about these sorts of things every now and then however. It is NOT acceptable at all. Meta-gaming, multiple accounts, and preset alliances are against the spirit of Diplomacy. People who engage in such underhanded techniques ruin the game experience for themselves and all other players in their game. They have no real good reason to do it either, as winning does not come with any sort of prize, all they win is a pitiful amount of ego, but apparently there are still lowlifes whose only comfort in life is that they win a few Diplomacy games, albeit through cheating.
Although, standards on meta-gaming vary from player to player. Some see it as a grander Diplomacy in the scale of things, but personally, I try to go into each new game completely openminded, and do not worry about past quarrels. Of course, it is extremely difficult, without total anonymity, to ignore players who you know are disloyal, or those who make excellent and faithful allies.