From The Truth About Guns:

Time to lay in a heavier supply of popcorn. Today the Supreme Court granted cert in Cargill v. Garland, the case challenging the Trump era bump stock ban. The about face by the ATF following the Las Vegas mass shooting came at the direction of the Trump administration. ATF, which had previously approved sales of bump fire stocks as legal accessories used regulatory fiat to do a 180 and reclassify them as machine guns.