Demon sysadmins, at least, can view the IWF list but only hijack DNS requests. A screengrab is shown below as evidence of this. Demon's implementation also means that a simple comparison of Demon DNS responses routing to proxy versus OpenDNS routing to the actual site generates a confirmation of the ban for anyone to confirm. The screenshot is evidence of both.
Update: It would appear that Picasa chokes on that large an image - the file is also here.