For a while about a decade ago there was a site called "noindoctrination.org" which data-based documentable complaints from college students being shut down or otherwise "punished" by liberal instructors and classmates for their opinions.
You could search by college or instructor or type of complaint, etc. The professors involved were notified of a complaint and given the opportunity to respond or rebut.
My recollection was that few of them did. One interesting thing was that it seemed like if one complainant filed a complaint, there would often be successive complaints, "pile-ons," if you will, about the same instructor or situation.
It was pretty good. Stingemeister me even contributed to them.
I got a 501 (non-profit) receipt from them so I might still have the name and physical addresss of the site owner.
The site shut down for unknown causes but I sure wouldn't mind seeing something like that re-instituted.
Terry