This story was on one of the history type channels quite a few years ago.
A couple of interesting points. They were treated worse than the Japanese and there really were Japanese Americans who spied for Japan contrary to what we are constantly told.
Yeah, the entire 442nd regimental combat team were a bunch of spies.
Both the FBI and US Naval Intelligence told FDR the Japanese Americans were no treat whatsoever.
There was also an extensive history of German and Italian agitation, spying, sabotage, and subversion before US entry into WW II. Fortunately, the FBI and other federal agencies did a good job of shutting it down. Arguably, mass internments proved unnecessary, but there was justification for them.