NYT: It`s not intuitive to have pity for Mark Zuckerberg, the 26-year-old co-founder of Facebook. But lately Mr. Zuckerberg, thought to be the world’s youngest billionaire, is facing salvos from all sides — including green activists. First, the Hollywood writer-producer Aaron Sorkin took aim at him in a completely unauthorized full-length feature film due out on Oct. 1 called quot;The Social Network.quot; Now environmental activists at Greenpeace International have produced an animated mini-film …