Sorry, that is BS. My father went to dental school with a guy whose family was interred. His father was a nobody - just a dentist, and they were interred for the duration. Oh, and they (citizens all) had to sell all of their belongings in 3 days - you can imagine the price they got compared to actual value.
These people were completely loyal, and they were royally screwed over because of their looks. One of the worst injustices ever perpetrated in this country by the government (treatment of the various Indian tribes being far worse, and over a far longer period of time) - and Scalia is right, it'll likely happen again. Except that this time it won't be an ethnic group, it'll be those that dare to oppose tyranny even by uttering the word "Constitution" at the wrong time. I, for example, will likely be on the list just for my tagline (and I'm sure that there are more reasons, but that alone will likely be enough).
For those that condemn Scalia for mentioning this, consider that maybe he was warning us. Consider also that if he is still alive at the time of such an event, he'll likely be killed, imprisoned or forced to resign because of "bad health" (which is to say that his family will be threatened). The good Justice knows which way the wind is blowing, and he wants to be remembered for being out there with his middle finger proudly raised.
From what I understand was that the Japanese farmers owned a lot of prime farmland in California that roosevelts cronies wanted to get their hands on.
Once they were interred, their farms went for pennies on the dollar.