This is the URL at the bottom of the latest teaser posters, and it redirects to a Facebook page:
https://www.facebook.com/themeninblacksuitsarereal

At the time of writing it already had 3261 likes, so expect that to reach 6 figures in a few months.

I’ve uncovered that there’s these Men in Black suits who monitor and police alien activity on earth. Up until now no one believes me, so I’m on a mission to prove that they’re real and that’s why I started this Facebook page. More soon.

The above first post there is pretty weak, considering it is obviously created by the folk at Columbia Pictures or someone they hired… and not an individual.

These look blurry up close, but from a distance you will recognize the two stars of Men in Black 3:

3D posters don’t really work unless everyone looking at it has 3D specs on, so they have wisely used a different type of optical illusion that everyone can appreciate (or puzzle over). Either way, you are bound to linger in front of the poster longer than usual.

The posters are made up of tiny “MIB³” logos, which when seen together to form a face.

Supposedly these were spotted in cinema foyers this week.

And… if you look at the very bottom of the poster, there’s a URL: TheMenInBlackSuitsAreReal.com