The popular fan fiction website Archive of Our Own (better known as AO3) is going through a sustained denial of service attack (DDoS) as of Tuesday morning. The site’s status update Twitter account first reported unknown issues in the early hours of Monday morning. Five hours later, the account confirmed that the issues stemmed from “a DDoS attack causing the servers to fall over.”

A few hours later, the account tweeted that the attack was by a “collective of religiously and politically motivated hackers.” A report from CybersecurityConnect said a group known as Anonymous Sudan claimed credit for the attack on Telegram, saying it was part of a larger attack targeting U.S. companies. The group is reported to have said that it was targeting AO3 because “the site is full of disgusting smuts and other LGBTQ+ and NSFW things.”

Archive of Our Own hosts millions of fan fiction stories about existing characters and intellectual properties, including stories that are both safe-for-work and stories that have erotic themes running through them.

However, as CybersecurityConnect notes, experts believe “Anonymous Sudan” isn’t a group linked to its namesake country at all and is instead a Russian disinformation group. Indeed, AO3’s Twitter support account reiterated this: “cybersecurity experts believe the group claiming responsibility is lying about their affiliation and reasons for attacking websites. View the group’s statements with skepticism.”

As of the time of this writing, Archive of Our Own is still down. The last update from the site’s Twitter account confirmed that it was still working to mitigate the attacks. Fast Company has reached out to AO3 for comment.