We are working on the problem which causes your characters to disappear, so stay calm and be patient. There was no break-ins, it's a data base bug.
Our DB makes backup copies every day, therefore there is no reason to worry. We apologize for the inconvenience. This problem will be solved very soon.
Upd. : x100 realm is up. Character display works as it should again. We apologize for the inconvenience one more time.