Now that Iranian President Mahmoud Ahmadinejad has spoken at Columbia University, it's on to the United Nations, where there's a tight security net. As many as 25,000 people from around the metro area and the country flocked to the U.N. to protest Ahmadinejad's visit. Many are demanding an end to Iran's nuclear threat. The NYPD's eye in the sky took security pictures. On the ground, beefy machine-gun toting cops provided an extra layer of protection for Israel's foreign minister as she demand Iran's president be reigned in by the world community. "There's a need to stop Ahmadinejad," Tzipi Livni said....