"Go back to where you came from and stop stealing our jobs."
Wow that is so witty and deep, the only trouble is that the migrants that would be competing for the sort of job you're likely to have would not be able to read your witticism.
Maybe you could have another set of t-shirts made up to hand out to the natives in Tanzania and Indonesia when you go visiting your preferred investments there.
"Go back to where you came from and stop stealing our resources".
