BRITAIN'S Prince Harry and his wife, Meghan, spoke on Tuesday about their campaign against social media negativity, with Harry warning of a "global crisis of hate" that was affecting people's mental health. The couple, known officially as the Duke and Duchess of Sussex, led an almost two-hour online discussion hosted by Time100 Talks with some of the experts with whom they said they had met this year in their bid to promote more compassion in online forums. "This is a global crisis. A global crisis of hate, a global crisis of misinformation and a global health crisis," Harry said in…