David Hockney is set to have his largest exhibition at the Fondation Louis Vuitton in Paris, featuring nearly 400 works. However, a photograph of him holding a cigarette has been banned in the Paris metro, causing controversy. Hockney criticized the ban as 'complete madness' and emphasized art's role in free expression. The exhibition curator, Sir Norman Rosenthal, also condemned the ban as censorship. Hockney has a long history of advocating for smoking, claiming it benefits his mental health.