Wordpress Mu embed not working for youtube, input, code, etc.

Today I wanted to publich a real quick post about how to embed a paypal button into your wordpress post. A topic that has been covered many times elsewhere (if you consult google), but yet many paypal buttons failed to hide the merchant’s email address which would result in evil spam to be sent. Anyhow, I thought posting this quick article would take max 5 minutes or so, but it turned out to be more difficult: Wordpress MU for security purposes does not allow specific HTML code to be included in posts or pages.
This is for security reasons, as mentioned before, because in a multi-blog environment people could post all sorts of crap to compromise your site, server and work, ultimately driving you nuts and causing all sorts of havoc.

After some Googling I found several interesting articles, most of them repeated themselves and said “well.. edit the ksas.php file in wp-includes” and then stated a long-list with many interesting HTML pieces. This works, but a plugin is more fancy I thought: so I googled on and found a plugin called “unfiltered” content Wordpress MU, released by the Wordpress guys. This is in so far cool, as you can either stick it in the mu-plugins folder and have it sidewide, or in the regular plugins folder and just activate it on a blog by blog basis. Since I am running this Wordpress MU installation on my own and do not have posts to monitor for “havoc causing script includes”, I decided to go for the plugin and enable it side-wide. This way I can upgrade my wordpress mu next time a new version comes out and keep my sanity (because by then I would probably have forgotten about the includes folder and the php file that I need to update every time…)

Hope this helps,
best,
jez