Dr. Peter Teleborian
Teleborian is one of the nastiest villains we've ever encountered. We know that he's in cahoots with the Section to keep Salander quiet, but then we learn something new about him when Salander and Plague hack his computer:
[F]orty-seven folders containing close to 9,000 photographs of explicit child pornography. She clicked on image after image of children aged about fifteen or younger. A number of pictures were infants. The majority were girls. Many of them were sadistic. (16.66)
He is also linked to a network of people who trade in those kinds of images. This isn't what we'd hope for from the director of a psychiatric hospital for children. These images are serious crimes in Sweden, which is why the Constitutional Protection Unit of the Secret Police got involved. So take that, Teleborian.
Now, we have to sit back and appreciate the irony of the situation. Teleborian gets caught because he keeps the most incriminating aspects of his life on his computer. The man literally gets caught in his own web of deceit. He believes his own lies about Salander. He is so bent on thinking Salander is mentally deficient in every way, he misses the fact that she's a) a genius, and b) specializes in hacking into computers to catch predators like him. He gets the Underestimater of the Year Award.