Stupid question. False dichotomy.
There could be a thousand reasons they are doing it.
Most likely to maintain law and order for all students' safety.
What was he doing immediately before being thrown to the ground? That seems to have been edited out. I presume you would say he was peacefully going about his own business…?
I find if folks are generally law-abiding they don't tend to get decked by police.
No, no it's not. I can't help it if you are hard of thinking but the pat/popular answer is rarely the right answer. You come across as pushing a narrative. Are you a paid shill? We get a lot of paid shills here.