After turning Twitter (now X) into a website only a mother could love, Elon Musk has again shown why we can't leave the public square to irresponsible leaders. Last week, he endorsed dangerous commentary, this time stoking the flames of antisemitism on the site he owns by engaging with antisemitic users and their violent content. He has rightfully been chastised – and major advertisers like Apple, IBM and Disney have stopped running ads – but we have to continue holding him accountable. Tell companies who advertise on Musk's platform they don't have to put up with disinformation and hate speech. Sign the petition urging them to immediately stop running ads on Twitter.