https://arstechnica.com/information-technology/2019/04/despite-call-by-ceo-to-rep-ilhan-omar-twitter-slow-to-block-harassment/

Just after Twitter CEO Jack Dorsey paid a visit to the White House on April 23, he called Minnesota Congresswoman Ilhan Omar about a somewhat related topic—death threats that had been made against her on Twitter following a post by President Trump himself.

According to a Washington Post report, Dorsey defended the decision not to pull Trump's tweet—a video that combined a single phrase from Omar's speech at a Council on Islamic Relations banquet with footage of the attacks on the Twin Towers. Trump captioned it all: "NEVER FORGET."  The post remains up.