Companies in Silicon Valley, California, America’s technology capital, recently hurried to remove a misleading video from their websites. The video was of a discredited researcher sharing several questionable or false theories about the new coronavirus, including that it was part of a plot by powerful people. However, internet companies could not take the video down quickly enough. Millions of people watched and reposted the 26-minute video called Plandemic, over several days. And it gained a huge following in Facebook groups that oppose vaccines or are protesting state leaders’ stay-at-home orders. The spread of Plandemic demonstrates how easy it is to use social media to quickly share possibly problematic material to lots of people. It also shows how difficult it is for platforms to stop that spread.