ENTER-POST-LEAVE flooding solution

At present theres nothing much we can do about these guys doing that type of flooding. Let me share you the facts why is that so:

1. These guys are using a small program as shown in Fig.1
2. He will preset the room he's going to flood & the garbled messages.
3. And after pressing the record of the mouse macro recoder,(See Fig.2)
he enters the room using the small program, post the garbled message,
then he leave.
4. Then stop the recorder. Now he is ready.
5. Finally, he set the macro recorder to play like a hundred times
repeat of what he just recorded.
6. Then he press "Play" and the flooding starts.

Suggested solutions:
Leave the room: Let him enjoy his lunatic display alone. Mobile users are adviced to
leave at once for this type of high-speed flood eats up a lot of
byte-usage in an instant due to rapid data transfer.
Lock the room: Fill up the room's 25-user capacity so he can not re-enter thus
making his life a bit harder because he can not stop the macro easily once started.
Call Admins: He might run away or be kicked by an admin. But even admins can not
just kick him because he (flooder) is not in the room all the time.

Fig.1 (the small program)

Fig.2 (macro recorder)