Theory on the Men In Black
Men in Black a term coined for the enigmatic force that shows up to defend government facilities and harass people who have seen UFOs or have been abducted. They are so good at intimidation very few will even talk about what they were told, seen, or anything regarding the UFO or Men In Black. Yet who are the Men in Black and How do they do what they do?
An interesting question that first needs a distinction made. What is a men in black agent? Well typically they show up in groups of three mysteriously and disappear just as mysteriously. Some are reported to act like they are from the 60s and are easily exited by normal everyday objects such as pens. Given these facts we can surmise one thing; Men in Black are not humans and are kept isolated from humanity. In fact we can go a step further and surmise that they don’t work for the government but a “third party” as it was put in “Decide whether we should show up.”  Simply put Men in Black are not the G-men who harass people but are an entire step above them.
An interesting question is now how do they manage to travel through a desert without getting dust on their car? The answer is simple, you don’t. It is a nifty trick which we can extrapolate the answer from again “Decide Whether we should show up” which gives the answer of Multi-Dimensional technology. Now even if the “Decide Whether We should Show Up” turns out to be false the idea does have other support from the ruins on Mars which are designed to represent Hyberdimensional physics. On top of that Russia has pioneered Scalar technology for well over 50 years and is supported by James Clerk Maxwell’s original equations. 
Since this would mean that these agents would be working for the “third party” as it were and not say aliens like the Grays; would account for why they are fascinated by regular objects, their lack of knowledge on humans and our behavior and why seem to harass UFO witnesses.
Where are the men in black housed then? That is an interesting question that until we have some inside source simply can’t be answered for sure. They could be housed in another dimension or even in some underground military base. Maybe one of the special bases such as Dulce or 51/62 (they are close to one another). Where ever they are they don’t seem to have much trouble getting to you and knowing who you are.
In conclusion The Men in Black will continue to be an enigma. For to identify such a group one would have to get people who are deathly afraid to talk, or get into a secret facility and neither of those seem likely to happen any time soon.
Decide Whether We should Show up http://projectmothership.isgreat.org/Decide_Whether_We_Should_Show_Up.html
Dark Mission The Secret History of NASA by Richard Hoagland