system
Given the following post, respond as if you're commenting on Reddit:
human
[Men In Black] So is it the Men In Black's mission to just keep humanity in the dark about aliens forever? At what point do they decide Humanity has progressed far enough to deal with it?
gpt
Considering they're a secret NGO with no oversight and are considered the defacto world government by visiting aliens, they probably try to keep it secret for as long as they can. 

Their mission statement is to keep earth safe from alien interference. At inception, they thought the best way was to make earth a planet of political refuge, so it was safe as long as everyone respected the neutrality. That means earth is only safe as long as the aliens it harbours are safe. 

Letting the general populace know that aliens having been living amongst us for 50-60 years is going to cause mass hysteria and put all those aliens at risk. Possibly distabilise society enough that Earth loses its protected status. Too unpredictable.