Ir absolutely is and this law needs to be repealed immediately.  We have the right to remain silent and everyone needs to strictly use it no matter what with any kind of cop especially a Fed. I wonder though if they even have to disclose who they are dor it to count as willfully lying to an FBI agent which lot of dictates one cannot willfully lie or mislead if they don't know who they are talking to and why but these dirty cops don't play by any kind of honorable rules.