Wikipedia has started to work in Shanghai. I was able to access most pages and thought I’d push my luck. So I looked up the page on Mao. That worked, then for Cultural Revolution, that worked. Really pushing it, I looked up Tiananmen, and a page about the actual square came up and worked. I followed the link to a disambiguation page and went to the the Tiananmen Square “incident”. Boom. The page fails to load and all pages on Wikipedia failed to load thereafter. My connection to Wikipedia was suspended for fifteen minutes or so, probably for seeking too much information.