Alright, I made an account JUST to comment in this thread because I couldn't stand it anymore.
***SPOILERS ABOUND IN THIS POST, STEER CLEAR IF YOU HAVE NOT SEEN THIS FILM YET***
Here goes:
The main problem I have is with people calling the concept unbelievable. To say that, you must be a stranger to planet earth yourself.
Here's the concept: A minority group of 2.5 million people is up against a majority group of 6 billion. Is it really so difficult to believe, given human history, that we would leave them in a walled off slum for 20+ years? Do you even *know* what human beings have been doing to OTHER human beings for CENTURIES?
I'm not going to get into a political/religious/racial debate here, but the fact is that humans show a depressing trend throughout our history. Discrimination, denial of rights, war, holocaust, segregation, etc for the power and wealth of a select few. And all of those things are done to the members of OUR species. Humans. People. Citizens of Earth. Do you mean to say, that suddenly present day when a giant hunk of metal floats in from space and drops of creatures that look to us like giant INSECTS, we would *not* all flip out, that we would suddenly get our sh*t together, lay out the welcome mat, and offer them the same courtesies, rights, and NECESSITIES that we won't even provide to our own SPECIES? Absurd.
We won't give enough food to the human beings we have here NOW, why would these insect/shrimp people from space be given special treatment? They wouldn't.
As for the idea of why don't they fight back with the kickass alien weapons blah blah etc...
2.5 million. 6 billion. If they basically declared WAR upon the human race they would be ERADICATED in weeks. Even with their technology, the sheer number difference would be enough. Would you screw your chance of ever getting back to your home planet for the sake of killing a couple aliens? (we're aliens to them, of course)
I think the concept is too real for comfort. It says something about us as a species, and I think the film did a perfect job of portraying it to us. I believe the reasons so many questions about why they are here and if they will be back or not go unanswered is because the film is from the human perspective. Given that this actually happened, there would be a million and two theories about the mothership in the sky, but nobody would really know.
Anyway, sorry for the wall of text, but I had to deliver the rant and straighten a few of you out. Thanks for the time. ;D