On April 10, Microsoft uploaded a film to its YouTube account about Marina Abramovic, the Serbian performance artist known for pushing her body to the limit. Ms. Abramovic's work can be violent, sometimes bloody, but the Microsoft video was more innocuous: It was focused on "The Life," in which museumgoers wear special headsets so that Ms. Abramovic seems to appear before them. The video was essentially some P.R. fluff for the tech company's role in the artwork. But in one corner of the internet, it was seen as ... evidence of a Satanist conspiracy. The YouTube clip racked up more than 24,000 dislikes. Microsoft took it down on April 14. Ms. Abramovic said ... that she had rarely spoken about her treatment by conspiracy theorists because she did not want to encourage them. She is breaking that silence now, she said, because she is fed up. The conspiracy theory goes back to October 2016, when WikiLeaks released hacked emails from the account of John Podesta, then the chairman of Hillary Clinton's presidential campaign. The emails included one from Ms. Abramovic, in which she discussed Mr. Podesta's invitation to a "Spirit Cooking" dinner at her home. Some internet users saw this as evidence that tied Ms. Abramovic to a wider conspiracy known as #PizzaGate, in which Mr. Podesta was said to be involved in a child-trafficking ring run out of a pizza parlor. Since then, Ms. Abramovic has received many emailed death threats " sometimes three a day, she said.