Here's Columbia University President's letter. It's embarassingly limp and mealy-mouthed.
I have two degrees from that excellent university, so I care. Here's what I would have written, were I in her shoes:
Dear Members of the Columbia Community,
As of today anyone who disrupts our educational mission will be arrested by the NYPD, and expelled. Students and and parents have spent a lot of time and money to receive what we have to offer, and it is our job to provide that.
If anyone decides that disruptive protesting is more important than learning in our excellent institution, they should do it elsewhere.
Sincerely,
Columbia University President Bird Dog