if he's using vB, then he must be using some mod like this
Allow Usergroups to Post HTML
Check this if you want to know how to create a BBCODE for youtube
[BB Code] YouTube embedded video
you can use the same way to embed videos from webridestv OR streetfire.
visit
this page of my site to see how I used bbcode to embed videos from different sites.
okk.. here's the setting
Allow HTML in Non Forum Specific Areas in vbulletin options->BBCODE settings.
But as it says
(Strongly not recommended.), you shouldn't go for it as allowing HTML in posts can be a security risk.