When aliens come to Earth in science fiction films, they treat us like animals, slaughtering us so they can use our resources or enslaving us because we are resources ourselves. And we get indignant and say in a shaking voice, "How could you?!"
What if there's life under the ice on Europa? What if the Em drive is crazy effective and we can get to Europa? What then? Do we REALLY think we're not going to take some Europa lifeforms back to Earth zoos? Of COURSE we will. But it's okay, because science.