that is something that hasnt yet been fully tested; but in theory if ppl used very big width or height values on tags that support these attributes such as tables and 3rd party tags. they could make posts very long or very large.
very large has been tested and its not such a big deal, only the post in question becomes very large but others remain normal.
i dont think i tested very long though but now that i think about it, it could be quite annoying.
anyways, for the moment if anyone ever abuses things such as this you can always use mod tools such as banning user or banning ip to protect yourself from the annoyers. and most ppl would never think of that (unless they have read this post).
but anyways, i will look for a solution to prevent that.
my first idea at the moment would be to add a code completely at the end of the bbcode rendering that just has a look at all width:xxpx; height:xxpx; and width=xx height=xx (maybe just those inside of <> html tags) and replaces the values that are too big by a fixed maximum.
maybe this feature could be implemented in the same parsing routine that i think i might add to cut off long words with no spaces outside of <> html tags