This refers to those individuals who never leave their cubicles at work. They never go into a plant, a factory, or the field ; they seldom leave their 4' by 4' space to lunch with fellow humans...(you get it). As soon as you read this someone you know came to mind...
I think you will have agree that old "B__" has carpet-feet these days, he cant seem to move from his desk anymore. Almost like his butt was glued to his chair...
What you say to someone who is violating your personal space out of aggression or stupidity. From the 80's street slang, you want them at least 6 feet away. Today, science reconfirms that mandate.
You and some friends are smokin a doob and some wannabe sidles up, all smiley and shit.
You: Hey, 6 feet fuckhead!