District 9 (2009)
This movie is a metaphor for environmental abuse and humanity's lack of empathy for any other creature, including themselves. This movie tells the story of an alien race that flees to earth when their planet collapses, and they plan on benefiting human society, but instead, they are greeted with violence. Unfortunately for humans, these aliens have much stronger weapons than we do, and they should have been nice when they had the chance.