Web sites serviced by DNS and hosting provider Go Daddy were down for most of today, but were back up later this afternoon. A hacker using the "Anonymous Own3r" Twitter account claimed credit for the outage.

"Things are restored," Go Daddy spokeswoman Elizabeth Driscoll told CNET just before 5 p.m. PT today. She said she did not have many details and was hoping to be able to give an update with more information in the next 24 hours.

In an interview this afternoon, Driscoll reiterated that she could not say what the cause of the outage was, and that she could neither confirm nor deny claims made by the owner of a Twitter account affiliated with the Anonymous online activist collective who has boasted of causing the outage with a distributed denial-of-service (DDoS). She also said she could not say how many sites were affected, whether it was thousands or millions, or whether the outage had affected just sites hosted by Go Daddy or those who use its DNS services as well. She did say the outage started just after 10 a.m. PT today.

"The problem is I just don't have a lot of information for you right now," Driscoll said.

The company updated its Twitter feed with this: "We're still working. Getting closer to normal. Thanks for all your patience and understanding."

The company had acknowledged the problem with a Twitter post earlier today that said: "Status Alert: Hey, all. We're aware of the trouble people are having with our site. We're working on it.

An updated message on the Go Daddy Support site read: "We are aware of an issue affecting several services, including email, our website and some customer websites. We understand your frustration. We want you to know that our team is investigating the source of the issue and is working to resolve it as quickly as possible."

In response to tweets from customers complaining about the outage and asking when it would be resolved, Go Daddy had tweeted: "Sorry to hear all your frustration. We're working feverishly to resolve as soon as possible."

The problem could be affecting thousands, if not millions, of sites, given that Scottsdale, Arizona-based Go Daddy is not only one of the biggest Web site hosters but also the largest domain registrar. The Go Daddy site itself was accessible earlier today for CNET but was down at last check. Twitter users were complaining that numerous sites hosted by the company were inaccessible.

A tweet from the @AnonOpsLegion account: "#TangoDown -- http://www.godaddy.com/ | by@AnonymousOwn3r" was the initial public promotion of the outage, leading some to believe that the Anonymous online activist collective was behind the disruption.

However, the AnonymousOwn3r account clarified in various tweets that: "it's not Anonymous coletive [sic] the attack is coming just from me."

"Duuude? This attack affects not only corporations but also ppl who support your ideology. whats the rationale?" one supposed fan of Anonymous tweeted.

Later, the AnonymousOwn3r account said in response to a question of whether he took down the whole block of DNS (Domain Name System) servers: "yes! it's not so complex."

That was followed by: "when i do some DDOS (Distributed Denial of Service) attack i like to let it down by many days , the attack for unlimited time, it can last one hour or one month."

And the AnonymousOwn3r account explained his actions. "I'm taking godaddy down bacause (sic) well i'd like to test how the cyber security is safe and for more reasons that i can not talk now."

AnonymousOwn3r was responding to some questions in Portuguese and in one tweet claimed he was from Brazil.

Updated at 4:59 p.m. PT with service restored for Go Daddy customers, at 4:43 p.m. PTto change headline and clarify in the body that cause is not clear, 1:25 p.m. PT with update from Go Daddy and 12:36 p.m. PT with more information from the AnonymousOwn3r account on how and why the attack was done, and message on Go Daddy Support site.