OpenAI has reportedly carried out a mass ban of accounts, with many users finding themselves unable to log in or discovering that their accounts had been deleted without any prior notice. The banned accounts are mainly associated with activities such as reselling or splitting free API quotas, multi-person account sharing, use of reverse proxy services, registration with low-cost region phone numbers, and student verification, among other types. Some personal accounts with no violations were also affected, though accounts with a prior record of violations were generally more likely to be banned. At present, speculation about the reasons behind the bans falls into two main categories: the more credible explanations include OpenAI cracking down on API quota resale, reverse proxying, and model distillation; follow-up actions after limits on the number of devices and payment cards bound to an account took effect; and the cleanup of violating accounts ahead of the new usage policy taking effect on November 20. There are also two less reliable coincidental associations. OpenAI has not yet issued a public statement on the matter, and its official help center only states that accounts violating usage policies or terms of service will be deactivated, and that users can appeal through an email link. There have previously been isolated cases of restoration after mistaken bans, but there has been no official admission of fault regarding this round of bans. Many banned users have lost chat histories, project context, and other content, with varying degrees of impact.