[Xenon]

yes it can be done very easy it think.
you have to edit functions.php the getpostbit-section

edit the postbittemplate

and add a small section to for example editpost.php to link at

but i don't think it's usefull, because post is edited, so everyone can change it

or do you talk about threads?
yes it's also possible then, but i don't think it's too usefull, because moderation of threads has nearly the same effect