A mysterious marketing agency secretly offered to pay social media stars to spread disinformation about Covid-19 vaccines. Their plan failed when the influencers went public about the attempt to recruit them. "It started with an email" says Mirko Drotschmann, a German YouTuber and journalist. Mirko normally ignores offers from brands asking him to advertise their products to his more than 1.5 million subscribers. But the sponsorship offer he received in May this year was unlike any other.