With vaccination against COVID-19 in full swing, social platforms like Facebook, Instagram and Twitter say they’ve stepped up their fight against misinformation that aims to undermine trust in vaccines. But problems abound. For years, the same platforms have allowed anti-vaccination propaganda to flourish, making it difficult to stamp out such sentiments now. And their efforts to weed out other types of COVID-19 misinformation – often with fact-checks, informational labels and other restrained measures, has been woefully slow. Efforts to crack down on vaccine misinformation now, though, are generating cries of censorship and prompting some posters to adopt sneaky tactics to avoid the axe.