Michael Hayden is a hack for security theater, and he makes big money in this line of work. So we should listen to him very, very carefully:

WASHINGTON -- Former National Security Agency chief Gen. Michael Hayden hinted Sunday at how the NSA's eavesdropping and data collection program is likely to evolve over time. Critics of the project have warned that by building the capacity to track the electronic communications of all American citizens, the government will inevitably be tempted to employ every tool it has at its disposal and scuttle whatever constitutional safeguards stand in the way. Not to do so eventually would in fact be more surprising, goes the argument.

In an appearance on CBS' "Face The Nation," Hayden -- also the former head of the CIA -- unintentionally opened a window into just how that evolution will likely unfold.

Asked by host Bob Schieffer about the president's proposal for a civil liberties advocate to argue on behalf of the Constitution in the secret court that oversees the NSA, Hayden said that such a setup would be inappropriate for fast-moving investigations. But he did float a hypothetical scenario in which such a safeguard might be appropriate: After an attack, he said, the NSA would want to use the vast store of information it has been collecting in more aggressive ways.

Hayden said that in general he was opposed to a civil liberties advocate's involvement in the process, and warned that slowing it down would lead to criticism.

"When you're looking in your rearview mirror after the next successful attack, this runs the danger of looking like bureaucratic layering," he said. "And, so, you need to be careful about how many processes you put in there even though I freely admit, you don't get to do this at all unless the American people feel comfortable about it."

He continued, adding that an advocate might be appropriate after an attack, when the temptation to overreach is greatest.

"This is no one's proposal," he cautioned, before unveiling his hypothetical. "You've got this metadata. It's now [currently] queried under very, very narrow circumstances. If the nation suffers an attack, there are other things you could do with that metadata. There are other tools. So in that kind of emergency perhaps you would go to the court and say, 'In addition to these very limited queries we're allowed to do, we actually want to launch some complex algorithms against it.'"

"That's the kind of argument that frankly, even I could accept you might wanna have an advocate there," he said.

In Hayden's hypothetical, the NSA would want to use an advanced algorithm to search through the information it had collected on American citizens. Such an algorithm could, for instance, read the email of every American, the type of search that is strictly prohibited by the Fourth Amendment.