Twitter has been disabled and taken offline in what Twitter are announcing as a coordinated attack on their servers.
According to the official Twitter blog the mirco-blogging site has come under denial-of-service attacks. It is believed that the Twitter servers have been flooded with data in a bid to disable them.
There has been no more official comment from Twitter on the attack or when and how it took place, but Twitter services have been removed for the time being.
Perfect Storm will update as soon as more information becomes available.