It's especially bizarre given that the majority of college students are 18+. What obligation do you have to the parents of a 20 year old? Your obligations are solely to your students.
No, they don't. They are fully aware of what they are doing, the history behind it, and the possible consequences of their actions. They are doing it because it is the right thing to do. In a time such as this, where the only voice you are left with is protest, then protest is the right way to use your voice.
