Scooter Libby is charged, among other things with Obstruction.
What does that mean?
It means when you say, as many people who are either stupid -- or more importantly think YOU are stupid proclaim, "Fitzgerald failed to find their was any original criminal activity" they are not being truthful.
Obstruction means, simply, if Libby hadn't gone out of his way to lie, destroy, or cover up his actions, we could tell you for certain. But rather than allow us to find out whether he broke the law -- he broke the law.
Not really that hard is it?