ElFroggio
Depending on the structure of the web content that is in the ibay, you could leave the ibay enabled for web access, add a new index.html with your message, and then use this howto
http://wiki.contribs.org/Htaccessto block access to subfolders.
Alternatively if a domain name is used to access the ibay, & that domain is configured in the Domains panel in server manager, then you could point that domain at a newly created but empty ibay that just has the message you want to display in the index.html file.