According to many customers, sites hosted by major web host and domain registrar GoDaddy are down. According to the official GoDaddy Twitter account the company is aware of the issue and is working to resolve it. Update: customers are complaining that GoDaddy hosted e-mail accounts are down as well, along with GoDaddy phone service and all sites using GoDaddy’s DNS service.
Update 2: Anonymous is claiming responsibility. A member of Anonymous known as AnonymousOwn3r is claiming responsibility, and makes it clear this is not an Anonymous collective action.