Comment: You can't ignore violent actions and physical threat against others.  Those are crimes and people should be locked up for them.  No matter whether it's protestors or counter-protestors.  We've been failing miserably at identifying and locking up thugs that commit violence, vandalism, and arson in the name of protest. The vast majority of them have been getting away with it scot free.

But as for people just running their mouths with extremist beliefs (that aren't physical threats or acts of violence), no, we should just ignore them.  That's protected free speech.  The effective way to combat that is to ignore it, and not give it a platform.