Can we have forced width on images?

One of the things I love so much about this forum is the strict rules that get applied here. The moderators here do a wonderful job at enforcing these rules.

Something that kinda bothers me is that when people post images that are wider then the thread and they stretched out of the area. I have proposed a fix to this by just adding in a max-width in the css. This will not work with IE6, but it will not affect the browsing, besides the images being to wide.