Will SOMEONE please reinforce the signature size guideline?

I have a list of people who are in clear violation of it, and their stupid signature friggen' takes up half of my computer screen (even on high resolution)!

I will post a list if this is not resolved within a week. I'm just sick of people posting huge pictures (which CAN be shrunken) and things and having to scroll down just to get to the post (which is always smaller).