" Always before, people ready to enter space have been civilized in a way you humans have avoided altogether. We fear if the people of Earth are allowed into space in their uncivilized state, the results could be disastrous beyond anything you imagine. At the moment, we are considering a permanent quarantine on Earth. We don't mind you exploring your own solar system; there's not much there anyway. But we cannot allow you to carry this sickness, whatever it is, into the galaxy at large. "
― Bruce Coville , My Teacher Glows in the Dark (My Teacher Is an Alien, #3)