Sinister

A couple houses down from us there is sometimes a car parked that has this sticker on its rear window:















My question is: what the hell does this sticker mean?

My old boss sold my ex-wife and me his station wagon and that had this sticker as well. Can't think of any car dealer around here that would use this -- at least I never see it anywhere. Plus that boss was formerly a full colonel in the Air Force, who has been to black sites and Area 51 and stuff.

And - OH SHIT! -- I have a tattoo of this on my back THAT I JUST NOTICED AND DON'T REMEMBER GETTING IT!

Please - while there is still ti-