It’s among the most iconic images of the last few decades — a picture of an unknown man standing before a line of tanks during the protests in 1989 in Beijing’s Tiananmen Square. In just one shot, the photographer, Jeff Widener, managed to convey a society struggling between the freedoms of individual citizens and the heavy hand of the Chinese militarized state. It’s also an image that few within China’s “great firewall” have access to, let alone see.