Twitter is in great problem, and it may not be the standard technical hiccup that the site experiences once in a while.
The ppl When trying to connect to the site, get an error message from browser it has received several tips stating that around 10 p.m. Pacific Time, the site was hacked and defaced with a message from a group identifying itself as the “Iranian Cyber Army.” The group may be using a DNS redirect to accomplish this.
Some covering the story say it is likely that Twitter has been so compromised, that account passwords might have been hacked as well. Tec Crunch has included an advisory that Twitter users should change their other passwords if they use the same one for multiple services.