We are aware that many people cannot load characters at the moment.
We were forced to switch to the new Armory community API, as Blizzard announced that they would be banning sites that used the old approach that we were using.
Things went well, and we registered with Blizzard as a high-traffic site.
Well... they banned us anyway for sending too much traffic to the Armory.
We are working to resolve the issue as quickly as possible. This will affect both users of the website and the mobile apps.