The push to remove witnesses may be the prelude to a Tehran Tiananmen. Yet a secret Internet lifeline remains, and it’s a tribute to the crazy, globalized world we live in. The lifeline was designed by Chinese computer engineers in America to evade Communist Party censorship of a repressed Chinese spiritual group, the Falun Gong.Today, it is these Chinese supporters of Falun Gong who are the best hope for Iranians trying to reach blocked sites.“We don’t have the heart to cut off the Iranians,” said Shiyu Zhou, a computer scientist and leader in the Chinese effort, called the Global Internet Freedom Consortium. “But if our servers overload too much, we may have to cut down the traffic.”