On the anniversary of the Tiananmen Square massacre, Microsoft blocked users of its search engine from seeing the photograph of “tank man,” the infamous protester pictured standing alone before a line of government tanks during the 1989 military crackdown. Searching for images of “tank man” on Bing temporarily returned only the message: “There are no results for tank man.” By contrast, Google brings up dozens of sites with the well-known image. After researchers and journalists in the U.S. and United Kingdom noted the difference, Microsoft said in a statement, “This is due to an accidental human error and we are actively working to resolve this.” A Daily Beast image search on Bing returned numerous tank-related images, but none of the famous Tiananmen Square photo. Commemorating the massacre is banned in mainland China, and authorities have scuttled a yearly vigil planned in Hong Kong.