Unwanted draft posts

I'm using a multi-site installation of Wordpress that has roughly 70 sites. Something is causing unwanted draft posts (with tags, too) to be created throughout my sites. Any ideas on what could be causing that? Is there any way for me to determine what the problem is without deactivating all of my plug ins? I've tried that already, but as far as I can tell there's no rhyme or reason to what's creating these draft posts. So, that means it would be a heck of a process to deactivate these plug-ins and figure out what's creating the problem.