The current system of bolco image tags does just that
it prevents the image from being seen, but the full
url to the image and the [img] tags are visible.
I had a little rant about it, as i think
it should prevent it being left behind.
I think were still going down the line of
good text bad text, and which is it in a signature.
I read on UBB DEV that someone edits the files in question
comments out the original and includes the words "HACKED"
then he can search for any changes, seems a good idea.