Shouting fire in a crowded theater is wrong because you don't own the theater, so you are violating the property rights of the theater owner. If you did own the theater and shouted fire anyway, you'd be defrauding your patrons out of a show they paid to see, and you'd be liable if anyone got trampled.
Nowhere is 'free speech' involved here. Free speech is the idea that the government will not use force to prevent or punish you for speaking on your own property or on the property of someone who is willing to have you.
If you break into an auditorium and give a speech with a stolen microphone, your ultimate arrest has nothing to do with the 'limits of free speech.' Likewise, if you use a pen or your mouth in the commission of a legitimate crime (such as fraud, assault, or murder), then free speech is not the issue.
Linking free speech to property rights carries a bunch of political and philosophical assumptions that are divorced from the legal history and realities of 1st amendment law in the U.S. Thats not just not how it works from either a legal or policy standpoint.
That's a fascinating question, actually. There are a couple of well-regarded approaches to including radio spectrum in a principled political framework.
The most historically congruent approach is to apply the principles of homesteading and private property rights, and allow courts to develop a common law framework for resolving disputes. Courts were beginning to do this successfully in the 1920s until the FCC was foisted upon us, with the effect of nationalizing the radio spectrum.
In practice today, this approach would mean privatizing the entire spectrum and allowing market forces to work, just as they do with all other forms of private property.
You can read Declan McCullagh's informed analysis of the modern harms the FCC causes and his detailed rationale for a property-based market approach here:
To better understand the importance of homesteading and property rights from a 'first-principles' analysis, I would recommend Murray Rothbard's _The Ethics of Liberty_, which you can freely read or download here:
In Rothbard's _For a New Liberty_, he addresses specifically the origins of the FCC and how the market approach was thwarted and replaced with bureaucracy:
An alternative approach is to treat the radio spectrum as a non-scarce good (like air), which perhaps is not that far from the truth in light of modern radio technology. Under this view, radio spectrum need not and should not receive recognition as property, nor should it be 'managed', regulated, or conserved by government.
Nowhere is 'free speech' involved here. Free speech is the idea that the government will not use force to prevent or punish you for speaking on your own property or on the property of someone who is willing to have you.
If you break into an auditorium and give a speech with a stolen microphone, your ultimate arrest has nothing to do with the 'limits of free speech.' Likewise, if you use a pen or your mouth in the commission of a legitimate crime (such as fraud, assault, or murder), then free speech is not the issue.