I literally think we should be able to scream 'fire!' in a crowded theater if the rules of the theater allow it.
I'm not saying someone should be allowed to walk in during a movie and start yelling 'fire' when private owners disallow it. I'm saying it shouldn't be some axiom of universal illegality. Also fully believe people should have the right to spread misinformation and actively encourage others to commit violence.
Where did I get such radical beliefs about free speech?
By studying the 1830s.
In the 1830s they, too, were worried about things like violence, misinformation, pseudoscience, etc. But, as history shows us, things weren't quite so cut and dry then and I think we'd be remiss to assume they are now.
For instance, in 1831, Nat Turner's now famed rebellion took place in Virginia. Dozens of white people from slaveholding families were killed and nearly 200 rebels were killed in retaliation.
Unsurprisingly, white slaveholders wanted to prevent such things from happening again, so state slave codes tightened up and an already repressive institution became yet crueler.
Most Northerners didn't pay it any mind, but a few William Lloyd Garrison-type abolitionists (kinda the far left treehuggers of their time) really picked up their anti-slavery efforts and, in many cases, adopted actively provocative and incendiary tactics.
Most notoriously to white Southerners, hardcore Abolitionists began a prolific mail campaign whereby they basically started mailing letter after letter after relentless letter to Southern slaveholders. This spam mail campaign bombarded plantation owners usually with appeals to reason in hopes they'd just have a change of heart and free their slaves. Sometimes, though, the letters came through like, "I send this letter in the hopes it will reach a tortured slave soul. If I am so fortunate, I implore you, KILL YOUR MASTER AND TAKE YOUR FREEDOM and may God be with you."
This was some legitimately incendiary stuff and these petitioners also spammed Congress with similar relentless letters.
It didn't take long for Southern statesmen to try and put an end to all this. State authorities carefully screened mail (itself arguably a violation of free speech) and, most controversially, Congress implemented a series of 'gag rules' to prevent provocative Abolitionist words from inciting further rebellion and bloodshed. Former President turned Congressman John Quincy Adams famously spearheaded the counter-movement in defense of free speech by personally opening up Abolitionist mail and reading it aloud.
Eventually the gag rules were overturned.
But the point is, the Abolitionist letters really WERE incendiary. Many of them really DID actively promote violence against the status quo or support 'domestic insurrection' as white Southerners would have called it.
I'm absolutely NOT trying to equate (insert modern purveyor of incendiary action here) to Abolitionists of old nor compare their causes.
I'm simply saying when you close the door on free speech, you're just as likely to shut down the modern day Abolitionist as anyone else. Incendiary speech may cause trouble but, in my opinion, that trouble will never be half as frightening as the alternative.
You may say, "OK but can we at least shut down speech we actively know to be untrue or scientifically false?"
Again, what if we used that approach in the 1830s?
At the time, the now discredited science of the day promoted highly racialized interpretations of human beings that actively supported things like white supremacy and attributed racial characteristics, some of which unfortunately resonate in the public consciousness to this day.
Your most educated, informed, cutting edge Ivy League education invariably made you very racist, unlike those silly, superstitious Abolitionists who insisted that "God made is all the same" and other such antiquated nonsense.
Science was decidedly not on the side of Abolitionists, most of whom essentially had to fall back on religious justifications for their belief systems and advocacy.
But that's the good thing about science. It's SCIENCE. It changes and evolves and remains in flux as we learn new things and, consequently, it doesn't have to fear dissent or questions or even misinformation.
You might say that what happened in the 1830s has no application to modern times. I simply disagree and I don't think we'll have any way of knowing for sure until 100 years from now when historians are looking back on our time from a position of comfort with all the variables we don't currently know easily accessible at their fingertips.
Our time is not so dissimilar as you might assume. Because, though the world changes, the human experience is universal. We're more than merely the product of our time and the power structures that be. Skepticism, dissent, and, yes, incendiary and radical voices, though dangerous, are also necessary and severing them ultimately does far more harm than good.