In the Washington Examiner, Timothy Carney warns that the NSA's PRISM program puts the United States on the slippery slope to tyranny:

Citizens that the federal government wants to indict, the federal government can indict if it monitors them closely enough. That's why it's so disturbing to learn that the federal government doesn't need to obtain a warrant on us in order to get our emails and phone records. But these surveillance powers are used only for hunting terrorists, Obama says. Even if you take him at his word, because so far there is no evidence to the contrary, think about the capabilities you give to government when it can snoop on your phone records and emails. Maybe Obama hunts only terrorists with it. But our next president could expand it to follow violent felons -- without having to get specific warrants. Why not drug dealers and sex offenders? Tax evaders come next.

When Carney writes that "the federal government doesn't need to obtain a warrant on us in order to get our emails," the "us" in that sentence seems to refer to U.S. citizens. But, in fact, the law requires that warrants must be issued to target communications between two U.S. citizens. As civil libertarian activist Glenn Greenwald admitted on Monday, " individual warrants are needed ... when two people are both inside the United States and are both American citizens."

So could the next president really use the NSA program to target U.S. citizens who are violent felons, drug dealers, or tax cheats, as Carney suggests? No. The president is barred by statute and the 4th Amendment from targeting U.S. citizens in such a manner. "Sec. 702 of FISA only permits targeting of non-U.S. persons outside the U.S. who are agents of a foreign power (i.e., either foreign spies or operatives of foreign terrorist orgs)," former federal prosecutor Andrew C. McCarthy told me in an email. "PRISM involves the implementation of 702, so the president can't 'expand' it in a way that would violate the statute, let alone the Constitution. The STATUTE would be infirm if it violated the 4th Amendment, so obviously the president's implementation procedures may not accomplish what the statute itself may not accomplish."

To repeat, the PRISM program is not designed to target electronic communications among American citizens. But that is not to say that the PRISM does not raise privacy concerns. The Washington Post claims that "a great deal" of American data can be "incidentally" scooped up by PRISM:

Analysts who use the system from a Web portal at Fort Meade, Md., key in “selectors,” or search terms, that are designed to produce at least 51 percent confidence in a target’s “foreignness.” That is not a very stringent test. Training materials obtained by The Post instruct new analysts to make quarterly reports of any accidental collection of U.S. content, but add that “it’s nothing to worry about.” Even when the system works just as advertised, with no American singled out for targeting, the NSA routinely collects a great deal of American content. That is described as “incidental,” and it is inherent in contact chaining, one of the basic tools of the trade. To collect on a suspected spy or foreign terrorist means, at minimum, that everyone in the suspect’s inbox or outbox is swept in. Intelligence analysts are typically taught to chain through contacts two “hops” out from their target, which increases “incidental collection” exponentially.

On the other hand, the administration claims that there are "extensive procedures, specifically approved by the court, to ensure that only non-US persons outside the US are targeted, and that minimize the acquisition, retention and dissemination of incidentally acquired information about US persons."

Michael Hayden, former NSA and CIA chief, said in an interview Sunday with NPR that analysts must immediately stop a search if they discover they're looking at American-to-American communications:

HAYDEN: PRISM is about Internet data, not telephony. And it's all about foreigners. All right? Now, so, if I've got a bad person in Waziristan talking to a bad person in Yemen via a chat room that is hosted by an American Internet service provider, the only thing American about that conversation is the fact that it's happening on a server on the West Coast of the United States. MARTIN: It's my understanding, though, that analysts who are making these determinations only have to be 51 percent sure that this person is a foreigner. That seems mushy. HAYDEN: Yeah, well, actually, in some ways, you know, that's actually the literal definition of probable, in probable cause. And I understand. It makes Americans nervous. Fifty-one percent; you're going to get some of these wrong. But, Rachel, the way this works is you get to do the first step, based on a belief that this is probably a foreign conversation. All right? But as you go through it, you are under a constant requirement to try to shred out whether you're still sure it's foreign or American. And if it's American, you're done.

It's fine to be skeptical of the government's claims. Some have turned out to be false. But we should also be skeptical of the  Washington Post and its source. Journalist Ed Bott notes that the Post has already changed its story once because it "took a leaked PowerPoint presentation from a single anonymous source and leaped to conclusions without supporting evidence." Furthermore, Bott writes:

In its original story, the Post calls the source of the documents "a career intelligence officer" who provided these materials "in order to expose what he believes to be a gross intrusion on privacy." We now know that the source was Edward Snowden, who was not an intelligence officer but an "infrastructure analyst" who had been in his current position with an external contractor for only three months. The "career intelligence officer" description seems exaggerated.

As Michael Moynihan writes at the  Daily Beast, Snowden seems to be a "deeply intelligent guy but also one who indulges in the conspiratorial." Snowden told a  Washington Post reporter that the U.S. intelligence community " will most certainly kill" the  Post reporter to stop the leak about the NSA. This is simply delusional. So long as you are an American citizen--and are not a  senior operational leader of al Qaeda camped out in some place like Yemen--there is no reason to believe that the American government will target you for assassination. That does not mean that other claims made by Snowden are necessarily inaccurate, but it should heighten our skepticism.

Back to the potential problem with PRISM: How many "incidental" American-to-American communications are collected by the NSA? And is it possible that emails between American citizens collected "incidentally" by PRISM might be shared with law enforcement officials to bust Americans for run of the mill crimes? We do not have a definitive answer.

The fact sheet issued by DNI James Clapper says that "the dissemination of information about U.S. persons is expressly prohibited unless it is necessary to understand foreign intelligence or assess its importance, is evidence of a crime, or indicates a threat of death or serious bodily harm." But is Clapper referring to "information about U.S. citizens" obtained through incidental collection of American-to-American communications? Or is he referring information about U.S. citizens obtained by legitimately viewing foreign communcations? A spokesman for the DNI did not respond to a request for comment from THE WEEKLY STANDARD.

No one has alleged that such "incidental" information obtained by the NSA has been shared with law enforcement officials. If it were, such evidence would likely be thrown out in court, since it was gathered through a warrantless search.

But the federal government should never be able to use American-to-American communications picked up through foreign intelligence gathering operations to arrest or prosecute U.S. citizens. If the FISA law needs to be amended to make it perfectly clear that the government cannot do that, then it should be amended, both to protect the rights of Americans and to protect a useful anti-terror program from being dismantled.