Recently, the visual portions of the website were hacked by someone claiming to be Algerian. They posted a ton of stuff across the site and put it into maintenance mode. It all seemed like basic copy/paste stuff, no subtle attacks or specific targets.
Looking over the systems they got access to, I have no reason to believe they got their hands on any sensitive user data, or gained any elevated access to the server as a whole.
I've updated the front-end security, which should stop this sort of thing in the future.