In 2000, Palestinian terrorists in Ramallah lynched two innocent Israelis, ripped them apart limb by limb, and held up their blood-soaked hands to a cheering mob. For many, the Artists4Ceasefire pin is an explicit reference to this incident. This problem extends far beyond awards ceremonies. “Together Alliance”, a new self-described “anti-far right” umbrella group, is gearing up for a major demonstration in central London on March 28. Many celebrities have put their names to the event, but so have several organisations that have been criticised for links to, or sympathy with, Islamist or antisemitic ideological positions. Many of these groups...