In the Detroit Free Press 4/12/06 there is an op-ed on free speech by conservative Christian writer and author Shaunti Feldhahn which promotes a widespread misconception on the nature of rights: that they can and should be legally restricted.
Ms. Feldhahn ends her op-ed with a quote from British jurist Henry Blackstone: "Speech is subject to (later) restriction by the police power for the protection of the moral health of the community."
Aside from the fact that the "moral health of the community" is the wrong standard of value for writing laws, the point here is that if speech can be restricted by law then speech is no longer speech by right but rather by permission which can be restricted further or even revoked.
It is not the government's restriction of Joe's speech, a negative, that forbids Joe from yelling fire in a crowded theater, it is the existence of a positive, their rights. If Joe were to yell fire in such a theater he would be guilty of using the use of force against the patrons by compelling them to dangerous even deadly behavior with false pretenses, a clear violation of their rights.
Putting it another way, Joe's right to yell fire in a crowded theater does not exist. Therefore, we cannot restrict that which does not exist. It is the govenment's legitimate duty to protect the theater-goers' rights that allowes it to throw Joe in jail, not any power to restrict Joe's right to free speech.
Some may say I'm playing with semantics. Not so. As our society grows ever more technologically advanced and complex, the need for intellectual precision becomes ever more vital. Look at all the confusion about patent and copyright laws as they pertain to the IT age. Philosopher Ayn Rand identified the proper framework for sorting these problems out: how best can we exercise our rights, not restrict them.
We must never think in terms of restricting rights.