UPDATE: I've received a response from the datacenter administrator, and some filters were reconfigured in an attempt to block the attack. If it doesn't help, the day shift administrator will analyse the traffic and reconfigure filters (in ~5-8 hours from now). I've been online on a character for over 15 minutes now without any kicks though, so it might have helped but I would suggest to play with caution if you're going to play at all tonight.
He's asking for shop coins, but he's not going to get anything. The e-mails he sent: