Article continues below advertisementDonald Trump may have opened himself up to unprecedented legal scrutiny by launching a $10 billion lawsuit against the BBC - as it's a move legal insiders tell OK! could force the U.S. president to testify under oath about his actions on January 6, 2021.Trump, 79, has filed his mega-money suit against the broadcaster as he continues to accuse it of defamation and unfair trade practices over the editing of a speech he delivered on the day of the deadly Capitol riot.Article continues below advertisementSource: MEGADonald Trump sued the BBC for $10 billion.