The FBI won’t step back from its dire warnings about warrant-proof encryption systems despite acknowledging that officials grossly overstated the number of instances in which encryption stymied an investigation, an official said Wednesday.

FBI officials have been warning since 2014 that warrant-proof encryption systems are allowing terrorists and criminals to “go dark,” recruiting and planning operations where the bureau couldn’t track them.

A major bolstering point for that argument was the FBI’s claim that there were approximately 7,775 devices that the bureau had a warrant to access but could not access because of encryption during the 2017 fiscal year.

That figure was incorrect, the FBI acknowledged Tuesday, because of flaws in the bureau’s methodology that led to “significant over-counting.”

The bureau is still investigating how many devices it actually couldn’t access during that time period, according to a statement. The Washington Post, which first reported the story Tuesday, said the figure could be closer to 1,000 or 2,000.

The fact the FBI’s numbers were incorrect does not shift the bureau’s conviction that warrant-proof encryption is “a major problem,” the bureau’s Associate Deputy Director Paul Abbate said Wednesday.

“Whatever that number is,” Abatte said, “each one of those devices represents a potential terrorist attack that could have been prevented or a child who could have been protected from a predator or an act of violence that could have been prevented across a range of issues.”

The FBI began to implement the flawed methodology in April 2016 but is reviewing all of its encryption figures from the past for possible flaws, Abbate said during an Aspen Institute cybersecurity event.

Abbate declined to say whether the bureau had lost credibility on the issue of encryption or if officials would do something to earn that credibility back.

Most technology companies and security experts have pushed back on the FBI’s calls for a workaround to warrant-proof encryption, arguing that any backdoor into those systems that allows for legal police access could also be exploited by criminal hackers.

The dispute centers on end-to-end encryption systems, which shield the contents of communication from anyone—including the service provider—except the sender and recipient. In other encryption implementations, the communications provider has an encryption key and can share decrypted communications in response to a warrant.

The flawed FBI figures are “a clear reminder that policymakers should take the FBI’s claims of going dark with a big grain of salt,” the Center for Democracy and Technology, a technology and civil liberties think tank, said Tuesday.

The Justice Department’s inspector general should also investigate how the figures became inflated, CDT Senior Counsel Greg Nojeim said.

Kevin Bankston, who leads the New America think tank’s Open Technology Institute, called for a similar inspector general’s investigation and called on the FBI to “finally drop its misguided crusade to undermine encryption.”

The inflated figures come on top of other reports that suggest the bureau may have overhyped the scope of the going dark problem.

A March inspector’s general report found the FBI did not explore all possible options in 2015 before trying to legally compel Apple to help break into an encrypted iPhone used by San Bernardino shooter Syed Farook.

The case was a signal moment in the encryption debate, but the FBI ultimately backed off of its demand after an unnamed third party offered to sell it a method for hacking into the phone.

One FBI division knew that third party’s fix was almost complete but wasn’t consulted before the FBI took the route of legally compelling Apple’s cooperation, the inspector general found.

An FBI employee who contacted the inspector general’s office was concerned that the leader of the Cryptographic and Electronic Analysis Unit was not actually interested in finding an alternative solution because he wanted to set a legal precedent compelling Apple and other tech companies to assist in future encryption crises, the report stated.

National security-focused lawmakers have mulled taking up the FBI’s call for a “legislative fix” to encryption, but none of their proposals have gained traction.

A 2016 report from Republican and Democratic leaders of the House Judiciary and Energy and Commerce committees urged against legislation that would weaken encryption.

Instead, the report said, law enforcement should explore other options such as gleaning information from unencrypted metadata—a common method used by U.S. intelligence agencies—or obtaining warrants to legally hack into encrypted devices.