Administration officials have defended the National Security Agency intelligence programs disclosed by former NSA consultant Edward Snowden by saying they are essential to national security and have uncovered over 50 terrorist plots. But several senators last week challenged the official line, saying that no plots had been uncovered through the bulk collection of American telephone records.

“So far, I’m not convinced by what I’ve seen,” Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., said of NSA claims that the telephone records collection program has been useful in stopping terrorist plots. He declared, “If this program is not effective it has to end.”

Certainly, it’s another good reason to curtail the program.

He rightly called the sweeping program a “massive” invasion of privacy. Sen. Mark Udall, D-Colo., went further, saying the bulk collection of phone records, although permitted by a secret federal Foreign Intelligence Surveillance Act court, is not only at odds with the language of Section 215 of the Patriot Act that allows collection of business records in connection with terrorist investigations but also with the Fourth Amendment’s prohibition of unreasonable searches and seizures.

Sens. Udall and Ron Wyden, D-Oregon, both members of the Senate Intelligence Committee, accused the administration of deliberately exaggerating the usefulness of the bulk collection of phone records by lumping it together with another program that allows the NSA to listen to foreign telephone calls and read foreign emails.

The senators also expressed frustration with secrecy rules that for years have prevented them from discussing the privacy issues raised by the NSA programs. While the public has been aware of them only for a short time, Sen. Wyden said they had been a concern of his since 2007.

Mr. Snowden, the fugitive former analyst granted temporary asylum by Russia on Thursday, clearly broke the law when he made information on the NSA programs public. But his disclosures also sparked the present level of open review and oversight. It’s about time.

And it is time to restrict Section 215 of the Patriot Act to its original purpose of giving law enforcement and the intelligence community access to records only when they can be shown to be part of a legitimate investigation.

The latest hearing should give impetus to legislation to restrict the NSA accordingly. Not only does the program raise constitutional issues, there’s the practical question — does it even work?