Way back in the 1970s a small town outside of Chicago was the epicenter of a discussion regarding these same questions: how far does freedom of speech go when that speech is utterly vile? Does freedom of speech mean that one is free from the consequences of their speech? Is a citizen free to scare, insult, or terrorize another citizen with their speech and/or actions? Are people free to speak when their actions may cause violence? 
Let me explain.
In the 1970s the town of Skokie, Illinois boasted a population of around 70,000 people. Of that 70,000 around 40,000 were Jewish and about 5,000 were actual Holocaust survivors (1). So, of course, the Nazi Party of America considered this the absolute best place to conduct a march. Of course.
The Nazi Party of America is exactly 
Founded in Chicago in 1970 by Frank Collin, the party was a spin off of the American Nazi Party that was founded in 1967 (arguably) by George Lincoln Rockwell. Rockwell was at best an opportunist exploiting the worst of humanity for his own egotistical needs or, at worst, an unapologetic racist bent on white supremacy in all areas of everything at the expense and exploitation of everyone else. (Note: I will not apologize for this assessment. Do not email me). Either way, Rockwell was assassinated in 1967 leaving the burgeoning neo-Nazi movement leaderless (2). Into the vacuum people like Collin formed their splinter groups and moved forward with their visions of white supremacy. And in Collin's vision in 1977 this meant a demonstration in a heavily Jewish neighborhood where members' Nazi uniforms and prominent swastikas would have the most impact.
what it sounds like-- a bunch of white dudes glorifying the national socialism that brought the world Hitler.
It's okay to call Frank Collin an asshole. Do the same for George Lincoln Rockwell while you're at it.
However, there was an unintended positive consequence born of this plan conceived in total fuckery. When the Cook County, Illinois circuit court issued an injunction prohibiting the marchers from displaying Nazi regalia, people everywhere began talking about what the first amendment means and how it applied in the Skokie case. Great American debate was resurrected. The ACLU jumped on board to defend the Nazi's free speech and the case traveled up to the US Supreme Court to become National Socialist Party of America v. Village of Skokie.
The Skokie case required review of first amendment protections on a host of issues. First, the city maintained that the swastika amounted to "fighting words" and that the march could incite violence. Further, they maintained that residents of Skokie were a captive audience that the city had a duty to protect. Considering these points, the court was tasked with determining whether or not the city could restrict speech and conduct on the basis that it was offensive and could cause outrage amongst residents. There's a lot of legal details here that can get confusing, but what is important is that, at the end of the day, the Nazis were
allowed to march (though they didn't), swastikas and all (3). 
So what does this mean for us today?
Well, it means that in the US you have a protected right to be a vile human being and express that vileness at your leisure and that you are not directly responsible for how people react to your expression of vileness (in most cases). Further, barring any actual kidnapping, no one is a captive audience, meaning that in most cases people have a protected right to ignore you. Or to tell you to shut up. These are important points to keep in mind as vileness remains a part of protected speech and continues to make its way into our political system and government. Especially this second point. You aren't required to listen to the vile shit coming out of people's mouths. And, further, if you are the one spouting the vile shit, other citizens have a right to tell you to cut the shit. They even have a right to drown you out in favor of something less shitastic and horrible. Like when those bikers refused to let the Westboro Baptist Church be heard (4).
Be the bikers. Drown out the shit. 
Also, the American Nazi Party survives today, you can find them online. I won't post their link directly because I think they are just the worst type of people. But I will post this super cool link I found to the FOIA documents released by the FBI regarding the party: https://vault.fbi.gov/American%20Nazi%20Party%20
3.) I have a great book about civil liberties in America that I cull a ton of information from:
Domino, John C. 2003. Civil Rights & Liberties in the 21st Century.
4.) The bikers that refuse to let the vitriol from the Westboro Baptist Church be heard:
There are some other fantastic examples of this, like the girl that drowned out anti-choice protesters by shouting about her yeast infection: http://www.slate.com/blogs/xx_factor/2015/10/26/yeast_infection_chant_breaks_up_planned_parenthood_protest_in_portland.html
