Our host's DNS servers were the victim of a long-lasting Distributed Denial of Service attack, which started yesterday afternoon. We apologize for this outage, but it was completely out of our hands.
This is the message they still have posted on their status page:
"A series of DDoS attacks on our DNS system has been rendering domains inaccessible since Tuesday night (December 9th, 2014). While we have already taken steps to resolve this issue, availability may remain limited. We apologize for any inconvenience caused."
DNS service is responsible for telling your browser where in the world a website is - without that, you can't reach a website at all, even to see a "We're having problems" message. Email also goes down when this happens, as mail servers must be able to find our mail system by looking up the address using DNS.
1And1.com indicates there could be further related system outages, but things seem fine at the moment.
We're looking at steps we can take to distribute our own DNS across multiple providers, as well as other solutions to make our systems bullet-proof, such as cloud hosting of all user files. We'll likely be moving image storage to the Amazon S3 storage services very soon.