Justin Ling is a freelance journalist who writes the Bug-eyed and Shameless newsletter. He is working on a book on police crowd-control tactics. Open this photo in gallery: Columbia University professors demonstrate outside the Columbia campus demanding the release of students, in New York City, on May 1.CHARLY TRIBALLEAU/Getty Images On Tuesday night, New York Police Department officers swept into Columbia University to arrest students for occupying their own campus. The mass arrest of students demanding that their school divest from companies supplying the Israeli military came 56 years to the day that cops arrested hundreds of anti-Vietnam War protesters...