[Goboom]

How would it be tough?
If they zoomed in too much you hold a button and click and it zooms out and it just distorts their forum view not others. As for the zooming, you could only zoom in on images that have the tag to view them used on it like the image would have to be shown using a tag like [imgzoom][/imgzoom] to zoom in on that image images with the regular {img}{/img} tag wouldnt be effected by zooming.