A federal judge's ruling Monday that the National Security Agency's bulk telephone metadata collection is "likely" unconstitutional is wrong on the law and the facts. It conflicts with the opinions of 15 other federal judges who have sat on the Foreign Intelligence Surveillance Court and approved the NSA's metadata collection 35 times since 2006.

U.S. District Judge Richard Leon has stayed his order to give the U.S. Court of Appeals for the D.C. Circuit the opportunity to reach its own judgment. But in the post-Snowden, anti-NSA climate pervading Washington, there is reason for concern that this opinion will amplify the caterwaul of those seeking to dismantle vital U.S. counterterrorism capabilities.

The telephone metadata collected by the NSA consists of transactional business records revealing only which phone numbers have called which numbers, when and for how long. It includes no other subscriber information, and it doesn't enable the government to listen to anyone's calls. This database enables intelligence agencies to discover quickly whether any phone numbers of known foreign terrorists have been in contact with numbers in the United States, a vital input in counterterrorism investigations. It is informative even when it reveals a lack of contacts.

In Leon's view, however, the Fourth Amendment prohibits Congress from authorizing bulk metadata collection and focused querying of the records, even where the president has determined its necessity and it is approved every 90 days by a federal judge. No case law remotely supports this breathtaking conclusion. Liberal use of exclamation marks is no substitute.

Leon argues that the Supreme Court's 1979 decision in Smith vs. Maryland upholding the warrantless use of pen registers — devices that record numbers dialed — has become obsolete in this age of multifunction smartphones. But district judges are not empowered to declare the death of binding Supreme Court precedent. The calling-record data collected by the NSA is almost exactly the same data the police collected in Smith.

In Smith, the high court held that telephone customers have no reasonable expectation of privacy in the numbers they dial or in the calling records that phone companies generate for business purposes. And since the court's 1967 decision in Katz vs. United States, a reasonable expectation of privacy has been the measure for what constitutes a lawful search under the Fourth Amendment. Appeals courts have consistently followed Smith and applied its holding to other developing technologies.

Although Monday's ruling emphasizes the "all-encompassing" and "indiscriminate" nature of the NSA's metadata collection, that does not alter anyone's reasonable expectations of privacy. If anything, the use of a pen register to target Smith's personal phone line was more intrusive than the NSA's metadata collection, given the vastness and anonymity of the data set and the minuscule chance that any particular person's calling records will be reviewed.

Leon believes that the metadata program intrudes on consumers' infatuation with their smartphones. But he fails to appreciate that individual privacy is much more porous today than it was in the 1970s. Many private companies collect and analyze personal data — including the Internet companies that want the NSA to stop its surveillance efforts. Most Americans willingly accept less privacy in exchange for the conveniences the Internet makes possible. But Leon's analysis means that U.S. intelligence agencies cannot protect Americans from foreign threats using the same analytical tools that private companies employ.

Judging the value of an intelligence program demands the greatest deference to the political branches; courts are not institutionally suited to the task. NSA metadata collection is both constitutional and necessary.

Michael B. Mukasey was attorney general in the George W. Bush administration. Steven G. Bradbury was head of the Justice Department's Office of Legal Counsel. David B. Rivkin Jr. served in the Justice Department and the White House counsel's office. They wrote this article for the Washington Post.