> What if you say it and someone is seriously harmed or dies as a result?
Frankly, that's the price of freedom, and it's the reason that fighting to maintain our freedoms is a never-ending battle.
Allowing the public to own and operate cars likely results in more deaths from crashes, but it also allows people to travel to and from arbitrary places on their own schedule.
Allowing people to own general purpose computing devices allows people to develop harmful software tools, to route around safeguards, to communicate clandestinely about illegal activities, and to design CAD files for 3D printed guns. Of course, it also brings us the ability to build software that works the way we want (or need) it to, to build successful businesses, to preserve ephemeral cultural history, to expose official corruption, and to organize political dissent through encrypted back-channels. You cannot have the benefits without the risks.
Allowing people to speak freely may result in someone feeling emotionally attacked, it may result in convincing someone that a false idea is true, or it may give people a flimsy excuse to engage in physical violence. But the benefits are innumerable. Unrestricted speech allows us to voice our concerns as citizens and participate in the political process without being silenced. It prevents the powerful from using concerns of "safety" to suppress dissenting opinions. It serves as a safety valve that helps potentially dangerous ideas rise into the sphere of public debate, where they can be taken apart (or even just "rounded off") before they result in something like genocide.
You can't stop speech, period. You can prevent it from happening publicly, on a temporary basis, but in the long term that kind of repression leads to violent revolutions.
That said, there must be some limits; I cannot run you over with my car or use my computer to hack the Pentagon, and I cannot threaten your life. But these limits must be explicit and narrowly constructed or they will be abused by the powerful. That means that there are necessarily "edge cases" that have to be decided by a fair and impartial process! This is unavoidable, because otherwise some people will continually step just over the line and then claim innocence. There is no way to "fix" this; it is always a messy process because of the enormous complexity involved in the world.
It's always tempting to trade freedom for safety, especially for victims who may not have suffered as much in a less free world. But we have to push back against that sentiment, or the future will not be worth living in.