I don't think they were serious.
Everyone here seems quite serious, however. The blonde fellow in the foreground, left of the above photo, is a professor who brought out several of his classes. I debated him for a couple minutes. I just noticed that he also is in the lower photo, watching. Maybe the crowd IS his class.
This crowd held forth for a whole afternoons. Our pro-life students did admirably under the intense heat of opposition. Aahh, the prof is in this photo too. I will say that he started off mischaracterizing us to his first class, which is what prompted my public discussion with him.