Apparently the “chilling effect” of Justice Department leak investigations on communications between government officials and the press has not been so chilling after all.

It certainly did not deter former CIA employee and National Security Agency contractor Edward Snowden, who has admitted that he is the principal source of recent leaks to The Post and the Guardian revealing top-secret NSA programs tracking terrorist communications.

The exposure of the PRISM program under which the NSA monitors foreign terrorists on the Internet, as well as the leak of a top-secret court order requiring Verizon to share calling data with the government, are incredibly damaging to national security. These leaks give terrorists information they did not have about our collection activities. They undermine the willingness of American companies to cooperate with us because these leaks have put their international reputations at risk. And they teach everyone — including sources and liaison partners — not to work with us because we cannot keep a secret.

But instead of being outraged by the damage done by these leaks, critics on the left and right are criticizing the NSA for undertaking activities that are lawful, constitutional and absolutely vital to protecting the country.

Calm down, folks. Big Brother is not watching you.

Ann Telnaes animation: The NSA’s data gathering technique (Ann Telnaes/The Washington Post)

During the Bush administration, critics opposed what they called “warrantless wiretapping.” Well, the leaked NSA operations are not warrantless. And, in the case of Verizon, they do not even involve wiretapping.

The Verizon court order shows that what is being tracked is not the content of the communications but the records of which phone number called which number, as well as the location and duration of the calls. In Smith v. Maryland , the Supreme Court held that there’s no reasonable expectation of privacy, and thus no Fourth Amendment protection, for the phone numbers people dial (as distinct from the content of the call), because the number dialed is information you voluntarily share with the phone company to complete the call and for billing purposes.

Why does the NSA need to collect all that data? One former national security official explained it to me this way: If you want to connect the dots and stop the next attack, you need to have a “field of dots.” That is what the NSA is collecting. But it doesn’t dip into that field unless it comes up with a new “dot” — for example, a new terrorist phone number found on a cellphone captured in a raid. It will then plug that new “dot” into the “field of dots” to find out which dots are connected to the new number. If you are not communicating with that terrorist, your dot is not touched. But the NSA needs to have the entire field of dots so it can unravel the network connected to that terrorist.

In the case of the PRISM program, the NSA is targeting foreign nationals, not U.S. citizens, and not even individuals in the United States. And all of this collection is being done with a warrant, issued by a federal judge, under authorities approved by Congress.

Not exactly 1984.

Moreover, what has been revealed are the “outward-facing” authorities of the NSA activities — what records the phone and Internet service providers are required to provide to the government. The leaks do not describe the many “inward-facing” restrictions directed by the Foreign Intelligence Surveillance Court to the government that describe the conditions and limitations on when and how the data can be accessed and how they can used.

Let’s pray those restrictions are not revealed — the terrorists would love to learn what they are.

If the critics don’t think the NSA should be collecting this information, perhaps they would like to explain just how they would have us stop new terrorist attacks. Terrorists don’t have armies or navies we can track with satellites. There are only three ways we can get information to prevent terrorist attacks:

The first is interrogation — getting the terrorists to tell us their plans. But thanks to Barack Obama, we don’t do that anymore.

The second is penetration, either by infiltrating agents into al-Qaeda or by recruiting operatives from within the enemy’s ranks. This is incredibly hard — and it got much harder, thanks to the leak exposing a double agent, recruited in London by British intelligence, who had penetrated al-Qaeda in the Arabian Peninsula and helped us break up a new underwear bomb plot in Yemen — forcing the extraction of the agent.

That leaves signals intelligence — monitoring the enemy’s phone calls and Internet communications — as our principal source of intelligence to stop terrorist plots. Now the same critics who demanded Obama end CIA interrogations are outraged that he is using signals intelligence to track the terrorists. Well, without interrogations or signals intelligence, how exactly is he supposed to protect the country?

Unfortunately, some on the right are joining the cacophony of condemnation from the New York Times and MSNBC. The programs exposed in these leaks did not begin on Barack Obama’s watch. When Obama continues a Bush-era counterterrorism policy, it is not an outrage — it is a victory.

And when those programs are exposed by leaks, it is not whistleblowing — it’s a felony.

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