I recently tried to participate in a Webex online demo. As I was in the process of logging in, I got a page that let me know I was officially out of luck, being one of those renegade Mac users.
I clicked the Continue button on this page, and wound up looking at this screen:
Check out the creative use of black-on-dark-blue, and the broken images. I guess this is additional punishment for trying to use a Mac – you don’t get to participate in the conference, and you get eye strain as a bonus.