There was virtually no danger from the Americans of Japanese, German or Italian ancestry. In fact one of the most decorated US Army units of WWII was the 442 RCT which was composed primarily of Japanese-Americans. The dangerous enemies of whom you speak were first-generation non-citizens with loyalties to their "homeland".
I expect a similar reaction from Arab(or Islamic)-Americans today. However, the only ones who should be interned are the foreign nationals who are not US citizens.
I've been mentioning internment, to remind that we ONCE took our own security seriously. Now, we act as if we wouldn't want to risk someone saying anything bad about us. That is partly why the events of Tuesday happened.
We probably over reacted in WWII, that much I will grant. Better to over react, than to under react, which is what I fear we are now doing. I believe that many were released, after initial internment. And I believe that from the procedure, we DID identify enemies of America.
Lest you get caught up in the mythology, there WERE disloyal Japanese origin people in America. THAT is one reason we took this measure, not then knowing it would later grow to be unpopular.
It is not unpopular, to this day, for my parents. My mother rivetted planes, and lived through the blackouts in Southern California. My Dad built the internment compound, at Heart Mountain, Wyoming, before earning a Purple Heart at Okinawa.
I'll settle for interning as many as possible, however unpopular. Sort them out and let the good ones go free. Deliver the bad ones to Saddam, of bin Laden, AirMail direct delivery atop a Cruise missile.