It cannot be tolerated because people are willing to commit and support acts of violence against those that use repugnant free speech. Whether it can be tolerated is orthogonal to whether or not it should be tolerated. I am merely commenting on the observation that more people than ever cannot tolerate free speech.
Understood. I read your comment as "I can not tolerate" or "we should not tolerate" when you meant more that society doesn't seem capable of tolerating it, when it should, which I strongly agree with.
Have they gone against those on the left who advocate and even perform violence against certain groups? Why haven't they taken active stance against these monsters who want attack others?