esel, no t possible afaik, with current code.
For educational scenarios we've requested to have the feature coded, and it does indeed already for wiki, forum, messages, file and image upload (I think), at least. (not Blog's, so far). But it's a question of time, and some more money for the developers to code it (go ahead! .
Previous work has been done by Sylvie.
Contact her, for instance, if you'd like this to be coded in short.