Submitted Feb 08 by Alexander Aghassipour
Zendesk’s RSS feeds require a reader that supports RSS Authentication (a username and password). Without that your RSS feeds and help desk data could be spilled into Google and made searchable by the public.
Recommended reader for Windows is FeedDemon:
http://www.newsgator.com/Individuals/FeedDemon/
Recommended reader for Mac is NetNewsWire:
http://www.newsgator.com/Individuals/NetNewsWire/
(the current versions of both Safari and Mail.app have authentication-issues)
If you are using host mapping for your Zendesk account, please make sure that the domain of the URL your are feeding your RSS reader is the non-host mapped version. I.e. "your_zendesk.zendesk.com".

This makes absolute sense for all the feeds within the logged in portion of the help desk, but what about the pinned items on the publicly available homepage?

Toby,
Public portions of your zendesk are available without any RSS authentication.