On October 3, the US Department of Justice asked Facebook to stop its end-to-end encryption program, urging the company not to move on without "making sure that user security is not affected." Attorney General William Barr sent an open letter to Facebook CEO Mark Zuckerberg, acting as Secretary of Homeland Security Kevin McAleenan, British Home Secretary Priti Patel and Australian Interior Minister Peter Dutton. Upon investigation, the letter has been published. Barr and other signers fear that end-to-end encryption will prevent law enforcement from dealing with illegal activities through the Facebook messaging platform. Facebook should "allow law enforcement to legally obtain content in a readable, usable format", effectively providing the back office with information to pass through WhatsApp, Instagram and Messenger. It will ask Facebook to work with the government to ensure this. In addition, it is reported that the United States and the United Kingdom will announce a data sharing agreement at the same time as the letter is issued.