Strictly speaking, a hoax is perpetrated when the hoaxers know that they are playing a trick on someone. The GWA seem to really believe their theory that the earth is heating up and that we are causing this warming by our misuse of our natural resources.
OK. "Hoax" is not the right word. I was using it in the more general sense of "fooling someone." What's revealed in the emails is systematic fraud, a concerted effort on the part of the GWA to manipulate, hide, and destroy data that falsify their predetermined conclusions. This is not science but politics. In some ways this is far worse than a mere hoax. Billions of taxpayers dollars/pounds/euros have been spent to combat this illusionary threat. Whole industries have been created with investment capital to address our destruction of the atmosphere. It is being suggested that these scientists and their more popular preachers be charged under RICO for conspiracy to defraud. Discovery on that case would be interesting!
True-believers in conspiracy theories (not the legal kind but the sort of kookie kind) have argued that global-warming hysteria is really about bringing the globe under a single government. This was easily dismissed as Chicken Little squawking. However, the newly elected president of the E.U., Herman von Rompuy, recently said in a speech to the E.U. parliament that he sees the Copenhagen Treat as just one move toward "global governance." Maybe the Chicken Littles aren't so chicken or little after all.
Though it goes without saying, I'll say it anyway: the hackers need to be found, arrested, and prosecuted. They have done the world a great favor. Unfortunately, they did it in an illegal manner.