DZ's "Sisters Only" side of the website is pretty much like what the other GLO's have. We've got our databases with contact info, a special section to order DZ-only jewelry, calendars for officers to look at in order to find out when their reports are due... just stuff like that. Nothing really "secretive." I think it's really more of a way to protect sisters' privacy from any sketchy people who might be trolling around the site.
It's definitely a safety feature, which is always nice to have.