A good one from The Peoples Cube

They trekked thousands of miles in searing heat...
They crossed the border risking life and limb...
They get paid peanuts...
They do jobs others refuse to do...
Some people back in their own country treat them with little respect...
They live crammed together in substandard conditions...
They rarely see their families...
They have to learn a foreign language and culture...
They recognize only one flag...

WHO ARE THEY?