John Oliver Is Buying Ads on ‘The O’Reilly Factor’ to Educate Donald Trumpbr PSAbr John Oliver Is Buying Ads on ‘The O’Reilly Factor’ to Educate Donald Trump About Sexual Harassmentbr The ‘Last Week Tonight’ host is trying to purchase ads to air during Bill O’Reilly’s Fox News program in order to teach the president a thing or two about sexual harassment.