On April 3, 2019, the House Ways and Means Committee made a formal request to the Internal Revenue Service for Trump's personal and business tax returns from 2013 to 2018, setting a deadline of April 10. That day, Treasury secretary Steven Mnuchin said the deadline would not be met, and the deadline was extended to April 23, which also was not honored, and on May 6 Mnuchin said the request would be denied. On May 10, 2019, committee chairman Richard Neal subpoenaed the Treasury Department and the IRS for the returns and seven days later the subpoenas were defied. A fall 2018 draft IRS legal memo asserted that Trump must provide his tax returns to Congress unless he invokes executive privilege, contradicting the administration's justification for defying the earlier subpoena. Mnuchin asserted the memo actually addressed a different matter.
On 4 April 2019, half a billion records of Facebook users were found exposed on Amazon cloud servers, containing information about users’ friends, likes, groups, and checked-in locations, as well as “names, passwords and email addresses.
On April 18, 2019, the company became a public company via an initial public offering. After pricing at US$36 per share, the share price increased over 72% on the first day of trading. The company was valued at US$16 billion by the end of its first day of trading. Prior to the IPO, Dropbox invested $5 million in Zoom.
On April 24, 2019, Facebook said it could face a fine between $3 billion to $5 billion as the result of an investigation by the Federal Trade Commission. The agency has been investigating Facebook for possible privacy violations, but has not announced any findings yet.
The 2020 presidential campaign of Joe Biden began on April 25, 2019, when Biden released a video announcing his candidacy in the 2020 Democratic party presidential primaries. Joe Biden, the former vice president of the United States and a former U.S. senator from Delaware, had been the subject of widespread speculation as a potential 2020 candidate after declining to be a candidate in the 2016 election. As a former vice president, Biden entered the race with very high name recognition. From his campaign announcement until late September, he was generally considered the front runner of the race and led the national primary in most major polls.