The Department of Justice published an open letter Thursday evening, asking Facebook to alter its plan to fully encrypt Facebook’s messaging services — Messenger, WhatsApp and Instagram — a move the company announced in March.

Attorney General William Barr and acting Homeland Security Secretary Kevin McAleenan, along with two top law enforcement officials from Australia and the United Kingdom are urging the tech giant to ensure that law enforcement agents have a means to access conversations when authorized by a judge.

A draft of the letter was first published by BuzzFeed News on Thursday.

In short, the officials are again asking for a digital equivalent of a wiretap, or what Department of Justice officials often refer to as “lawful access.”

Attorney General William Barr Mark Thiessen / AP

“Companies should not deliberately design their systems to preclude any form of access to content, even for preventing or investigating the most serious crimes,” the letter argues. “This puts our citizens and societies at risk by severely eroding a company’s ability to detect and respond to illegal content and activity, such as child sexual exploitation and abuse, terrorism, and foreign adversaries’ attempts to undermine democratic values and institutions, preventing the prosecution of offenders and safeguarding of victims. It also impedes law enforcement’s ability to investigate these and other serious crimes.”

On Friday, Barr and other top officials are expected to speak at the Lawful Access Summit about warrant-proof encryption and its impact on child exploitation cases at the Department of Justice in Washington, DC.

Facebook acknowledges the needs of law enforcement but wants to protect its users from unwanted snooping.

“End-to-end encryption already protects the messages of over a billion people every day,” Andy Stone, a Facebook spokesman, said in a statement. “We strongly oppose government attempts to build back doors because they would undermine the privacy and security of people everywhere.”

In July, Barr warned of the dangers of “warrant-proof” encryption, echoing a position that has been held by many top American government officials across multiple administrations going back to the Clinton Administration, which warned that encryption “can be used by terrorists, drug dealers and other criminals.”

In recent years, Department of Justice officials have not fully explained how they would achieve the end goal that they seek through federal law or executive authority, and there has been no substantive movement in Congress.

Thursday’s letter has been met with resistance by Silicon Valley, including from the Computer & Communications Industry Association, an advocacy group of tech firms, including Facebook.

“Strong encryption is increasingly vital to the privacy and security of individuals, national security and economic prosperity,” Ed Black, CCIA’s president, said in a statement. “Companies should be encouraged to develop and employ the security standards that the public expects for their devices and online activity. ”

Meanwhile, in recent weeks, a host of technical and legal experts convened by the Carnegie Endowment for International Peace concluded that there should eventually be some middle ground on the issue and encouraged advocates to continue to find a meaningful solution to the vexing problem.

“Cybersecurity advocates should not dismiss out of hand the possibility of some level of increased security risk, just as law enforcement advocates should accept that they may not be able to access all of the data they seek,” they wrote.