Planetary Quarantine is a term in the modern-day that is used by people who want to make the colonization of other celestial bodies as slow and excruciating as possible.
It can be used in the future however as a way of stopping diseases or other such things from exiting the planet and spreading to other ones.
It is also used by some people on Earth as something we should do to Earth and Humanity in general, saying things like "We should fix our own planet first" and another such nativity. These people typically don't realize that Earth is doomed and that humanity, in the long run, can only survive in the Stars.
"Bro fuck Billionaires!! There should be a Planetary Quarantine on Earth, man! Humans suck!"