Jeffy Yu was days away from his 23rd birthday when he appeared to take his own life Sunday in a video. A flattering obituary appeared, calling the aspiring crypto mogul “a visionary artist, technologist, and cultural force” and “a tech prodigy from an early age.” A memecoin in Yu’s honor went up for sale.But in the days that followed, online sleuths raised doubts about the video’s authenticity. The obituary disappeared. Whatever deceptive game was being played came to an indisputable end when Th...