Ban some Image Hoster?

[Tunnox]

Hello,

I was looking for an Addon to Ban some famous Image Hosters from my own Forums. The User should use my own Image Hoster and not imageshack.us,imgur etc..

Is there any Addon to Ban Image Hosters and say to users they sould use our own Image Hoster?

Or do i need to use the censor Function in vBulletin?

Sorry for my bad english.

sincerely
Tunnox