The vast majority of Twitter accounts that pumped out fake news during the 2016 presidential campaign are still active, a report has found. Researchers pored over millions of tweets and concluded that more than 80 percent of the accounts associated with the 2016 disinformation campaign are still posting. That’s despite Twitter patting itself on the back in July after carrying out a purge of fake accounts. The research was carried out by the nonprofit Knight Foundation. “The persistence of so many easily identified abusive accounts is difficult to square with any effective crackdown,” said report authors Matthew Hindman of George Washington University and Vlad Barash of the social-media analysis company Graphika.