WASHINGTON — Facebook executives told Attorney General William P. Barr on Monday that they would not open up the company’s encrypted messaging products to law enforcement, escalating a standoff with the government over privacy and policing.
In a letter from the company, the executives overseeing Facebook’s WhatsApp and Messenger, Will Cathcart and Stan Chudnovsky, wrote that creating a so-called backdoor into their services would make their users less safe.
“The ‘backdoor’ access you are demanding for law enforcement would be a gift to criminals, hackers and repressive regimes, creating a way for them to enter our systems and leaving every person on our platforms more vulnerable to real-life harm,” the executives said in the letter, which was obtained by The New York Times. “It is simply impossible to create such a backdoor for one purpose and not expect others to try and open it.”
The letter was sent ahead of a Senate hearing on Tuesday about encryption, at which Facebook and Apple executives testified. Mr. Barr is expected to speak about the nation’s largest tech companies later in the day.
Facebook’s statement was the latest volley in a yearslong fight between tech companies and law enforcement officials over how to balance privacy and security with digital communications. It has ensnared not only Facebook, but also Apple, and it promises to become more intense as more messaging services become encrypted.
In 2016, a federal judge ordered Apple to help the Federal Bureau of Investigation unlock an iPhone tied to a 2015 mass shooting in San Bernardino, Calif. The agency ultimately unlocked the phone without Apple’s help, easing tensions for a time.
Mr. Barr renewed the debate this year, saying that Facebook’s moves toward end-to-end encryption, which shields the content of messages from everyone but the sender and recipient, makes it harder for law enforcement officers to track malicious behavior online. The technology makes it harder to investigate child predators and terrorists, he has said.
Mr. Barr, joined by his British and Australian counterparts, wrote an open letter to Facebook’s chief executive, Mark Zuckerberg, in October asking that he take steps to enable “law enforcement to obtain lawful access to content in a readable and usable format.” Companies, they said, “should not deliberately design their systems to preclude any form of access to content even for preventing or investigating the most serious crimes.”
Lawmakers of both parties echoed those concerns on Tuesday, questioning whether tech companies’ commitment to absolute encryption was causing harm.
“You’re going to find a way to do this, or we’re going to do this for you,” said Senator Lindsey Graham, Republican of South Carolina and the chairman of the Judiciary Committee. “You’re either the solution or you’re the problem.”
Throughout the hearing, Facebook and Apple representatives said the companies were committed to working with law enforcement, and detailed how they detect malicious content despite encryption.
Encrypting its messaging products is the central aspect of Facebook’s plan to rebrand itself as privacy-focused after being battered for years by revelations that it mishandled user data. But it has also put the company, which is already the subject of consumer privacy and antitrust investigations, on another collision course with governments around the world.
In recent years, Facebook has undergone a networkwide shift from spreading information openly through the News Feed to more private channels, like Messenger, WhatsApp and Instagram Direct. As users have flocked to one-to-one and private group messaging, it has become more difficult to root out the spread of illicit material — drugs, child pornography, firearms trafficking.
The network has come under intense criticism for the role private messaging has played in the proliferation of misinformation. In the months before the Brazilian presidential election in October 2018, WhatsApp groups created by anonymous users spread misleading voting and candidate information.
In most regions outside the United States, WhatsApp plays an outsize role in how people communicate with one another, usurping standard text messaging and other methods. Facebook’s strategy, led by Mr. Zuckerberg, has been to seize on that popularity, directing Facebook to focus more on private and group chat experiences.
In March, Mr. Zuckerberg unveiled a grand plan to encrypt and knit together the back ends of the company’s messaging services, an enormous feat of back-end infrastructure work that could take years. The move could eventually help Facebook monetize those services, which account for relatively little revenue.
“We think it is critical that American companies lead in the area of secure, encrypted messaging,” Jay Sullivan, who oversees privacy and integrity for Messenger, told lawmakers at Tuesday’s hearing.
David McCabe reported from Washington, and Mike Isaac from San Francisco.
This is a developing story. It will be updated.