You can get the rss feed of the recent changes which would include any code you add to a page.
RSS Feed:
http://www.crackedeggstudios.net/wik...anges&feed=rss
(you have disabled the feed presumably to not show the code)
Furthermore, you can see the diff history of any page and see the code. This is just too easy to see the 'hidden code' that it is (unfortunately) ineffective at best.
For example, see this page:
http://www.crackedeggstudios.net/wik...anges&days=100
From there, you can look at this page:
http://www.crackedeggstudios.net/wik...293&oldid=2292
This page clearly shows the 'protected content' and the CODE.
To make matters worse, you could view the raw page and see the full current page with all of your code and the hidden content:
http://www.crackedeggstudios.net/wik...ent&action=raw
EDIT: If anyone is going to say something like, "well...this is just to hack or someone who tries to see hidden code" you are fooling yourself.
A simple search also shows hidden content. Someone could search for something as simple as the word "links" and show 'hidden content' (since the search engine has no idea it is supposed to be hidden from that user).
http://www.crackedeggstudios.net/wik...searchx=Search
Again,
this mod should NOT be used to hide or protect content under any circumstance. It just doesn't work. If you want to protect or hide content, I would wait until there is an extension that will tie categories or pages to user groups and then use the vbwiki tool to match wiki user groups and vb groups.
Seriously, a wiki is not designed or intended to protect or show content. It is a tool to openly share information where everyone can edit it. If you need to hide or protect information, mediawiki is not the tool you are looking for.