is there a way to prevent signature scrolling?

I'd like to look into preventing the scroll bar in the signature area.
The idea behind that is that people are starting to realize they can put ANY size picture or image or whatever in there and it will expand or scroll or whatever. I'd like to prevent scrolling in all browsers to discourage such huge images from being used (it also slows page load a lot) and locking the scroll means if they do post a large images in their signature, people would only see the top few pixels of it, maybe making think twice?

So, how can one prevent the side scroll bar so that one can't scroll up and down in the sig area??

Thanks, I guess I'd forgotten that.