The launch of a new chatbot by Chinese artificial intelligence firm DeepSeek triggered a plunge in US tech stocks as it appeared to perform as well as OpenAI's ChatGPT and other AI models, but using fewer resources. By Monday, DeepSeek's AI assistant had rapidly overtaken ChatGPT as the most popular free app in Apple's US and UK app stores. Despite its popularity with international users, the app appears to censor answers to sensitive questions about China and its government. Chinese generative AI must not contain content that violates the country's "core socialist values", according to a technical document published by the national cybersecurity standards committee. That includes content that "incites to subvert state power and overthrow the socialist system", or "endangers national security and interests and damages the national image".

A strange thing happened last week when you searched for "tank man" on Google. Tap on image results and instead of the usual photos of Tiananmen Square in Beijing, and the iconic image of a brave protester staring down a convoy of tanks that was captured in 1989, the first result was the same historic moment – but from a different point of view. For a time last week, the first result on Google Images for "tank man" was instead an AI-generated image of the same protester, taking a selfie in front of the tank. The image was created by Midjourney, and was at least six months old. First reported by 404 Media, a new tech journalism startup set up by former Vice News staff, the emergence of the tank man selfie – which Google subsequently removed from search results for "tank man" – highlighted one of the main fears that Eddie Perez, Twitter's former head of election integrity, highlighted to me in a recent podcast interview: it's now possible, with the use of AI imagery, to create alternative history. And that has huge ramifications not only on our lives, but also our elections.

Microsoft Corp. on Friday blamed "accidental human error" for its Bing search engine not showing results for the query "tank man" in the United States and elsewhere after users raised concerns about possible censorship around the Tiananmen Square crackdown anniversary. Users, including in Germany and Singapore, reported Friday that when they performed the search Bing returned the message, "There are no results for tank man." Hours after Microsoft acknowledged the issue, the same search returned only pictures of tanks elsewhere in the world. "Tank man" is often used to describe an unidentified person famously pictured standing before tanks in China's Tiananmen Square during pro-democracy demonstrations in June 1989. Microsoft said the issue was "due to an accidental human error and we are actively working to resolve this."