The chair of the House Oversight committee has revealed that Ivanka Trump and Jared Kushner illegally used private email accounts and messaging apps to carry out official White House business. In a letter to the White House Thursday, Maryland Congressmember Elijah Cummings said Kushner—President Trump’s son-in-law and senior adviser—used WhatsApp to communicate with foreign contacts, including Saudi Crown Prince Mohammed bin Salman, while both Kushner and his wife, Ivanka Trump, used private email accounts in a way that appeared to violate federal records laws. Cummings also revealed that White House officials, including Steve Bannon, used personal emails to discuss transferring sensitive nuclear technology to Saudi Arabia. During the 2016 campaign, Donald Trump repeatedly led chants of “Lock her up!” as he blasted Hillary Clinton for her use of a private email server as secretary of state.