PureZC's host (NOT PureZC itself), called Linode, has been hit continuously with DDoS attacks since Christmas. These attacks were mostly focused on Linode's data center at Atlanta, which is where PureZC is hosted. Because of this, PureZC has been down for a pretty long period of time during which Linode has been attempting to mitigate the DDoS attacks. It seems like they are, for now, successful in their mitigation. However, while PureZC is currently working, keep in mind that issues may persist while Linode attempts to completely recover from the attacks.
Thanks, and Happy New Year!