The EVE Online Facebook page has word that CCP has been forced to take EVE Online, DUST 514, and their websites offline due to a denial of service attack (thanks Massively). Here's word:

At 02:05 GMT June 2nd, CCP became aware of a significant and sustained distributed denial-of-service attack (DDoS) against the Tranquility cluster (which houses EVE Online and DUST 514) and web servers.

Our policy in such cases is to mobilize a taskforce of internal and external experts to evaluate the situation. At 03:07 GMT, that group concluded that our best course of action was to go completely offline while we put in place mitigation plans.

While we initially reopened EVE Online and DUST 514, we have since re-evaluated. With the highest sense of precaution we have taken Tranquility and associated websites back down for further investigation and an exhaustive scan of our entire infrastructure. We will update you more frequently via our Twitter feed (www.twitter.com/eveonline), however, an extended service interruption of several hours is expected as this process should not be rushed.