Real boss

Staggering around Home Depôt the other day looking for something or other and a clerk, noticing my distress, came over and asked:

"Whatcha lookin' for, Boss?"

Boss? Several times in the last couple of years I've been addressed that way, but before that, never. Where did it come from? Is it a rap thing? An artifact of the prison-industrial complex? It's weird, and vaguely insulting. Whatever happened to "May I help you, sir"?

The Urban Dictionary lists 94 definitions of the word. Number nine:

An employee of the state or county entrusted to guard prisoners; the prison guard, the jailer, the warden, the bailiff. The Man.

Number 11:

Disingenuous form of address used by insolent little twats, which although ostensibly deferential, actually implies that they don't actually have any respect for you at all.

"Alright boss!"

"Thanks boss!"

Yeah, that's it.