Microsoft’s Tay chatbot was taken offline roughly 16 hours after launch

Microsoft took its Tay chatbot offline roughly 16 hours after launch in March 2016 after the bot posted inflammatory tweets, with Microsoft attributing the suspension to a coordinated attack that exploited a vulnerability. Microsoft's post-mortem said the company had prepared for many types of abuse but made a critical oversight for this specific attack, which the source frames as a gap between preparing for known attacks and testing against adversaries. The source argues a red team would have probed repeat-after-me instruction hijacking, coordinated multi-user pressure on a learning loop, and escalation across many turns before launch.