The example doesn't work as described for me; not sure if I haven't followed it right, or there's a problem with the code. Can someone help me to determine what the problem is.
Specifically, after adding the authentication code to the PostsController, with this line:
before_filter :authenticate, :except => [:index, :show]
The guide says that "we want the user to be authenticated on every action, except for index and show", however, it only authenticates on the new post and edit options; it doesn't authenticate on destroy.
Sincere thanks in advance to anyone who can help shed light on this
issue! 
Here's my code: