Stop spam posts in vbulletin by blocking text
 

Is it possible to stop spam posts in vbulletin by blocking text like the "$" symbol if so how?

I have users signing up spamming dj equipment but to top it of is fraud also.

I tried the usergroup promotion setup but its annoying having to approve posts/threads

So is it possible that when someone tries to use "$" in thread title and/or post that it bans their ip lol. my site is .co.uk so only use GBP anyway :D