Isn't "undocumented" a nicer way of saying illegal?

If only every country took this kind of measure, the world would be less of a tinderbox right now.

Swedish crime rates soaring since these fine examples of modern globalisation started entering their country in droves.

French people can't even take a metro to work without worrying about attacks.

I invoke my right under the 5th amendment of the United States constitution and decline to answer the question.