Before Banksy even picked up his first can of spray paint, Richard Hambleton (aka "the godfather of street art") was putting his shadowmen all over the city. Each shadowy figure was created out of black paint and a brush, and in the end they landed on hundreds of buildings around town. Location was important to Hambleton, as he wanted the figures to surprise unsuspecting pedestrians (he says that once he was even scared by his own shadowman). He seemed to enjoy the element of surprise even when he started what he called his "public art" in the 1970s.
Prior to his shadowman series, he had been making chalk outlines on the streets, which Vandalblog noted a few years ago "would get picked up by the local media, as residents in suburban and generally wealthy communities mildly panicked about the 'crime scene.'” He had done over 600 by the end of the series.
Here's an old interview with Hambleton—in the beginning you'll see Allen Ginsberg standing against one of his shadowmen, before the artist talks about his early work and the statements attached to it:
He didn't always keep his work within city limits, however—in 1984 he painted 17 life-size figures on the east side of the Berlin Wall, and he returned a year later to do the west side. (Sounds kind of familiar.) This was around the time these photos were taken by photographer Andreas Feininger.
Hambleton—who still resides on the Lower East Side, where he became a recluse for decades—is the only surviving member amongst his contemporaries, Keith Haring and Jean-Michel Basquiat.
Maybe he'll do a collaboration with that guy currently visiting from the UK?