embedding videos vs html
 

In a hidden forum on my vB site I've enabled html. Then I got a copy of the embedded link from a youtube and put that link into a post. The video played great.


I found this thread made by Jake on how to put up embedded youtube tags
http://www.vbulletin.com/forum/showthread.php?t=199304

My question is: when the youtube tags are enabled, can people put up any html? If so is there a security issue?