Thousands and possibly millions of websites hosted by GoDaddy have crashed in an apparent attack by hacking collective Anonymous.
A member of Anonymous has claimed credit for downing the web hosting firm, which manages millions of websites around the world.
AnonymousOwn3r, identified as the "security leader" of the loosely organised hacker group, took to Twitter to confirm responsibility for the outages.
"Hello http://godaddy.com/ now yes! all servers #tangodown by @AnonymousOwn3r," a tweet said, using the code word for a hack attack.
When some news sites blamed the attack on Anonymous, the same individual responded on Twitter by saying: "it is not Anonymous coletive it's only me don't use Anonymous coletive name on it, just my name."
GoDaddy hosts over 5 million websites. Those reporting outages included MixForSale.com and video sharing site You-Watch.org.
GoDaddy issued its own statement on Twitter: "Status Alert: Hey, all. We're aware of the trouble people are having with our site. We're working on it."
The company added later: "So many messages, can't get to you all... Sorry to hear all your frustration. We're working feverishly to resolve as soon as possible."
The purported hacker, when asked about his motivation, tweeted; "I'm taking godaddy down bacause well i'd like to test how the cyber security is safe and for more reasons that i can not talk now."
Another message said the attack had no specific time frame: "it can last one hour or one month," the tweet said.