At some point around 10pm PST on 17 December, it seems like Twitter got hacked by a group calling itself the "Iranian Cyber Army". The DNS for the address was redirected to another site, but the API continued to function normally.
The group, whoever they are, posted a message on the front page saying "U.S.A. Think They Controlling And Managing Internet By Their Access, But THey Don’t, We Control And Manage Internet By Our Power, So Do Not Try To Stimulation Iranian Peoples To. NOW WHICH COUNTRY IN EMBARGO LIST? IRAN? USA? WE PUSH THEM IN EMBARGO LIST".
During the Iranian election period, Twitter made a much-reported rescheduling of some site maintenance upon request of the US government, as protesters against the government were using it to coordinate action.
The company has now updated its status blog, saying: "Twitter’s DNS records were temporarily compromised but have now been fixed. We are looking into the underlying cause and will update with more information soon".
When that happens, we'll update this post too.
UPDATE: Twitter has issued the following statement on its blog:
"Domain Name System or DNS is an Internet protocol used to translate IP addresses into domain names so instead of typing in a long string of numbers we can enter urls like www.twitter.com into a browser to visit our favorite web sites. Last night, DNS settings for the Twitter web site were hijacked. From 9:46pm to 11pm PST, approximately 80% of Traffic to Twitter.com was redirected to other web sites. We tweeted,blogged, and updated our status page last night.
"During the attack, we were in direct contact with our DNS provider, Dynect. We worked closely to reset our DNS as quickly as possible. The motive for this attack appears to have been focused on defacing our site, not aimed at users—we don't believe any accounts were compromised. If you're concerned that your account could have been affected in some way, feel free to contact us, accountsafe [at] twitter.com."