So, as we all know, the U.S. declared war on Japan in December 1941 and then Rutherford died just a few weeks later. The following memo to J. Edgar Hoover from an FBI agent in San Diego indicates that a custodial detention card was indeed issued for J. F. Rutherford, but since he was already dead, the card was ordered to be destroyed:
So Rutherford possibly came close to facing internment had he lived a little bit longer.