Libby has just been convicted of lying to the FBI (and not for anything else underlying the case).
Martha Stewart had the same thing happen to her.
The clear message being given by the federal government is "assert your fifth amendment rights" and don't cooperate. Faulty memories are not a defense and the war on the people removed reasonable prosecutors years ago.
The other message is don't be a public servant - you'll get indicted.
My prediction - the FBI and others will be complaining in the near future that white collar types will no longer talk with them - and it is unethical that they don't cooperate.
What is unethical is that attempts at cooperation will now get you charged with ambiguous crimes like obstructing justice - whatever that is (I have an idea it is all in the eye of the beholder).
Oh what a sad state of affairs.