So the Chancellor of the University of California put out a defense of free speech when violent rioters threatened to cancel a talk by a far-right agitator at Berkeley (see following item). So the violent rioters overwhelmed the insufficient force of municipal and campus police and canceled the speech. Then what have we learned here? That high-minded statements unaccompanied by not enough law-and-order often do little or nothing for free speech.
What to do? The same thing we advise whenever this happens: don’t let the censors win. Be sure to invite the speaker back, even if it is the obnoxious Milo Yiannopolous, after negotiating enough local police and enough rent-a-cops to handle the feral young. This will make your commitment to free speech very clear.