Why do I get the "Insufficient Privileges" error page?

To be able to view an object (article, folder, blog, etc) on the site, you must have adequate privileges.  For example, if you created the item, then you are the owner and can always view it.  If you are trying to view someone else's object, then it must be either visible or published.  If the the object is private, then you will get the "Insufficient Privileges" error.

All objects come into the world in a private state when you create them.  Then, when you want other people to see them you can make them visible.  Oh, there is an exception...  Comments and discussion posts start out as visible, so you don't have to do anything special for everyone to see them.