The image of one of my profs, who always used the classroom as his personal soapbox, will always stick with me. After showing his hostages, er students, a Youtube video of a WTC building collapsing, he turned and spat out "How does steel turn to dust!". And that was the clincher supposedly. I argued and needled him a bit during the semester, but I regret not reporting his unprofessional behaviour to the dean and/or the college allumni.
And think he should have been applauded.