As of Monday afternoon, all sites being hosted by Internet domain registrar GoDaddy were down. The company confirmed the issue on Monday afternoon via Twitter and is working to resolve the problem.

"Status Alert: Hey, all. We're aware of the trouble people are having with our site. We're working on it," tweeted GoDaddy.

GoDaddy customers complained that their hosted email accounts are also down. When trying to access their own sites, users are met with database errors.

Update (2:50 p.m. ET): GoDaddy has not yet said what's responsible for the server outage, but a Twitter feed owned by Anonymous is claiming responsibility. After GoDaddy tweeted its services were down, @AnonOpsLegion tweeted, "#TangoDown -- godaddy.com | by @AnonymousOwn3r."

GoDaddy was attacked earlier this year for backing the controversial Stop Online Piracy Act (SOPA), even though it quickly pulled its support of the bill after the Internet attempted to boycott GoDaddy's services.

More on this news as we receive it.