Britain's Prince Harry, singer Elton John and five other high-profile figures' privacy lawsuits against the Daily Mail began on Monday with the start of a trial at the High Court in London. Here's everything you need to know about the trial and what's at stake.Who is suing?Prince Harry, King Charles' younger son and the Duke of Sussex, music legend Elton John, John's husband David Furnish, actors Liz Hurley and Sadie Frost, campaigner Doreen Lawrence and former British lawmaker Simon Hughes are suing Associated Newspapers Limited.