Most likely involving members of the black community "posted up" on their front steps...or "stoop". Usually for a duration of time longer than the normal 8-hour workday. Most likely dressed in white-T's, sometimes involving brown paper bagged 40's, and occassionally joints behind the ear.
"You would not believe how many stoop monkeys are out today"
this is a person who congregates on their "stoop" leading up stairs to their shack. This occurs normally in poor neighborhoods. stoopmonkey can also be used as a slang word for a black person.
God damn nigga...go back home you stoopmonkey!