Microsoft has blamed “accidental human error” for its Bing search engine blocking image results for the phrase “tank man” after users raised concerns about possible censorship around the 32nd anniversary of the Tiananmen Square military crackdown.
Users, including in the United Kingdom, United States, Germany and Singapore, reported a search on Bing for the image of a lone protester standing before tanks during pro-democracy demonstrations in the Beijing city square in June 1989 returned the message, “There are no results for tank man.”
China censors references to the deadly crackdown on protesters and has never allowed public events on the mainland to mark the anniversary.
David Greene, a civil liberties director at the nonprofit Electronic Frontier Foundation, said that content moderation was impossible to do perfectly and “egregious mistakes are made all the time”.
But he said it could be more sinister: “At worst, this was purposeful suppression at the request of a powerful state.”
China is known to require search engines operating in its jurisdiction to censor results, but those restrictions are rarely applied elsewhere.
Hours after Microsoft acknowledged the issue, the “tank man” search returned only pictures of tanks elsewhere in the world.
Microsoft said the issue was “due to an accidental human error and we are actively working to resolve this”.
Smaller search engines such as DuckDuckGo that license results from Microsoft faced similar issues around “tank man” searches and said they expected a fix soon.
Rival Google showed many results for the famous image when the “tank man” search was performed on Friday and Saturday.
Hundreds of people gathered near a Hong Kong park on Friday despite a ban on an annual candlelight vigil to remember the Tiananmen Square events for a second straight year.
Earlier in the day, police arrested Chow Hang Tung, a vice chair of the Hong Kong Alliance that organised Hong Kong’s vigil, for publicising an unauthorised assembly on social media.
After the vigil ban was issued, Ms Chow urged people to commemorate the event privately by lighting candles wherever they are.
Additional reporting by agencies