Britain’s Prince Harry said he warned the chief executive of Twitter ahead of the Jan. 6 Capitol riots that the social media site was being used to stage political unrest in the U.S. capital. Harry made the comments Tuesday while he was taking part in an online panel on misinformation in California. He said he made his concerns known via email to Twitter CEO Jack Dorsey the day before the riot. “Jack and I were emailing each other prior to January 6 where I warned him that his platform was allowing a coup to be staged,” Harry said at the...