Bob Novak, in 2001:

Three and half-years ago, I reported that a veteran FBI agent resigned and retired after refusing a demand by Attorney General Janet Reno to give the Justice Department the names of top secret sources in China. My primary source was FBI agent Robert Hanssen.

Disclosing confidential sources is unthinkable for a reporter seeking to probe behind the scenes in official Washington, but the circumstances here are obviously extraordinary. The same traitor who delivered American spies into the Kremlin's hands was expressing concern about the fate of intelligence assets in China. ...

...why break a reporter's responsibility to keep his sources secret? I wrestled with this question for months and finally decided that my experience with Hanssen contributes to the portrait of this most contradictory of all spies. Furthermore, to be honest to my readers, I must reveal it.

Bob Novak, this week, when asked whether Senate Republicans had been feeding him confidential memos electronically pilfered from the Democrats:

Novak declined to confirm or deny whether his column was based on these files.

"They're welcome to think anything they want," he said. "As has been demonstrated, I don't reveal my sources."

Some people look at this juxtaposition, and see only naked partisanship. But I discern adherence to a single, consistent principle. The consistent principle is this: Novak will never burn a source, no matter how criminal or egregious the conduct of that source, not even if (as in the Valerie Plame case) tipping off Novak was itself a transparently criminal act -- so long as that source stays in a position to feed him more illicit dirt down the line...

The point, of course, has also been made elsewhere...