Apple and Google should reconsider their plans to enable encryption by default on their smartphones, and the U.S. Congress should pass a law requiring that all communication tools allow police access to user data, U.S. FBI Director James Comey said.

Comey, repeating his recent concerns about announcements from Apple and Google to offer new encryption tools on their smartphone OSes, went a step further Thursday, when he called on Congress to rewrite the 20-year-old Communications Assistance for Law Enforcement Act.

Following the past 15 months of leaks about surveillance at the U.S. National Security Agency, the pendulum of public opinion has swung too far away from law enforcement’s needs, Comey said in a speech at the Brookings Institution.

CALEA requires telecom carriers to give police access to telephone conversations, but Comey called on Congress to expand it to cover the wide range of communication apps and devices not anticipated by lawmakers in 1994.

New encryption tools, combined with a huge number of communication tools not covered by CALEA, means law enforcement agencies are often “going dark” when attempting to track down criminals and terrorists, Comey said.

“I’ve never been someone who is a scaremonger,” he added. “But I’m in a dangerous business. So I want to ensure that when we discuss limiting the court-authorized law enforcement tools we use to investigate suspected criminals, that we understand what society gains, and what we all stand to lose.”

Comey said his goal with the speech was to open a dialog about law enforcement access to communications, and several audience members pushed back against his call for more surveillance capabilities.

Asked about NSA surveillance, Comey said he understands why companies are marketing encryption tools. The push for privacy “comes from justifiable surprise on the part of the U.S. as to the extent and nature of the surveillance being conducted,” he said. “I can understand people being freaked and surprised, but I’ve yet to see the rogue conduct, the lawless conduct, that people talk about.”

However, the scope of some of the surveillance was “breathtaking” to people outside the law enforcement and intelligence communities, he added.

Other audience members questioned the international implications of increased law enforcement access to all communication tools. If U.S. law enforcement agencies demand access, so will other governments, said Greg Nojeim, senior counsel at digital rights group the Center for Democracy and Technology.

“If you’re Apple, or you’re selling Androids, you can’t sell an NSA/FBI-ready phone in Europe,” he said. “Are you expecting them to build two kinds of iPhones, two kinds of Android phones? Are they going to have to build three or four or six kinds when other countries follow our lead?”

Comey said he hasn’t thought through all the international implications. “I can imagine them saying, ‘we as an American domiciled corporation, will comply with ... requests from the U.S. government in connection with lawful investigations,’” he said. “Where we may get is to a place where the U.S., through its Congress says, ‘we need to force this on American companies,’ and maybe they will take a hit.”

Even as the FBI worries about going dark, many Internet and electronic device users are concerned about “going bright,” said Cameron Kerry, a former general counsel and acting secretary of the U.S. Department of Commerce. “There’s a tremendous amount of digital information that is available to companies and to governments,” said Kerry, now a visiting fellow at Brookings.

U.S. policy on access to digital information could drive international norms, Kerry said. “If we go down this road and take steps that would break encryption, what is the impact on more repressive countries around the world that will follow that example?” he said.

Comey’s speech also drove an active debate on Twitter. “I oppose requiring companies to build back doors into their products,” tweeted Senator Ron Wyden, an Oregon Republican.

Comey gave examples of four investigations, including a child sex abuse case and a child murder, in which he said information from smartphones was significant in getting convictions. If encryption is standard on smartphones, those convictions would be much more difficult, he said.

“I like and believe very much that we need to follow the letter of the law to examine the contents of someone’s closet or someone’s smartphone,” he said. “But the notion that the marketplace could create something that would prevent that closet from ever being opened, even with a properly obtained court order, makes no sense to me.”

He called on the country to have a debate about the proper level law enforcement access to communications, after revelations of NSA surveillance may have lead to an overreaction. “Are we so mistrustful of government—and of law enforcement—that we are willing to let bad guys walk away, willing to leave victims in search of justice?” he said.