True Names pdf von Vernor Vinge
Disaffected computer wizard "Mr. Slippery" (True Name Roger Pollack) is an early adopter of a new full-immersion virtual reality technology called the Other Plane. He and the other wizards form a cabal to keep their true identities — their True Names — secret to avoid prosecution by their "Great Adversary" — the government of the United States.
The lines that define us are not always black and white, though. There's a new wizard in the Other Plan and they're recruiting for a scheme to translate cyberspace domination into real world power.