The big movie over the weekend was David Fincher’s “Social Network,” AKA “The Facebook Movie.” And while its filmmakers took liberties with the facts to build a broad appeal, the story of Mark Zuckerberg’s brainchild still resonates with tech entrepreneurs, as well as the mainstream audience that spent $23 million in the film’s opening weekend. Takeaway digital editor Jim Colgan followed 300 such techies, who rented out their own movie theater in Midtown Manhattan, to find out why.