AO3 operator OTW says it found evidence of a security incident and expects the service to remain down for at least two weeks, potentially four, while investigating. Works, bookmarks and kudos have not been deleted, but theft of the account database containing usernames, email addresses, IP addresses and hashed passwords has neither been confirmed nor ruled out. OTW advises changing passwords on other sites where the AO3 password was reused. Donor information is stored in a separate system and was not exposed in this incident. Limited or read-only access may return earlier, but further interruptions could follow.