Let me explain what the M.I.B's actually are and what they do. Don't judge me 'cause I haven't watched an M.I.B movie in a while. Not my fault, I don't have them.

The M.I.B's mission as a whole is that they monitor extraterrestrial beings and activity on the planet, even friendly chat with them. They are invisible to the public and the government, not having information of them on government computers and systems. They are determined to keep their organisation a secret por asking quick preguntas with the witnesses of odd activity, then modifying their memories afterwards so they forget what they saw.
Oh yeah, and they exist in shadow...