Mr. Green tended to flit about as a child, but with focus: he built go-karts using lawn mower engines; he ran the New York City Marathon when he was 16; he dropped out of the University of Pennsylvania just months before graduation — accepting a degree, he felt, would be capitulating to a corrupt social structure — and he spent much of his 20s squatting with a community of anarchists in abandoned homes in west Philadelphia, where he “rescued” food that restaurants had planned to throw away and distributed it to homeless people.