Bump.
Announcement:
You can now ban certain users from entering your channel! :D
To do this you right click their name, go to set channel group, and set them to Channel Banned. After you do this, kick them from the channel and they will be unable to re-enter.
One small issue though. If you were to ever want to un-ban the user, you would have to get a moderator, administrator, or me, to move them into that channel and then you can change their channel group to a normal user.