(CNN) — Former FBI Director James Comey was interviewed by US Secret Service agents at their Washington, DC, field office on Friday afternoon, according to law enforcement sources. Comey was interviewed by agents investigating a social media post he posted Thursday showing shells in the sand on a beach spelling out “86 47,” which has become a popular social media code for removing Trump from the presidency. Comey was not in custody and appeared voluntarily, a source said. Trump and fellow Republicans have attacked Comey for the post, demanding an investigation. Comey “knew exactly what that meant,” Trump said in...