I can't believe I have to explain this, but I'll play ball.
It's a caricature of the way Natives are treated by the majority of Americans. As you personally demonstrated, as have others, you consider the treatment of the Native American protestors just.
When white Americans obstructed the Government whilst armed to the teeth with weaponry, they got a slap on the wrist. When unarmed Native Americans protested the destruction of the environment, and the poisoning of their fresh water, they were set upon with attack dogs and pepper spray; you condoned the actions of the security personnel that attacked the protestors.
And in this very thread, you, along with Buckshot and Imported_Tajmahal, supported the actions of the police using water cannons on the Native Americans, in freezing temperatures. You supported them using tear gas and pepper spray, and were rather quick to deem the protestors as terrorists. But not the brutalizing police, oh no, they're in the right.