What type of speech can government restrict?

Answer 1

The government can restrict speech that threatens public safety and welfare, that endangers national security, or that incites violence. Laws also exist that govern slanderous speech.

In the United States, there are generally two forms of speech: commercial, and all other.

Commercial speech is generally defined as speech involved in the sale of products, whether in advertising, contracts, warranties, or other aspect of commerce. In such areas, the Courts have decided that the government can have broad leeway in restricting speech. Laws against false advertising, overtly restrictive or punitive contracts, and limits on personal service are thus legal. For instance, it is not possible to state "Product X cures cancer" in an advertisement, if you cannot produce actual factual studies that have show such. Likewise, a warranty cannot state that the product isn't intended for any specific use, and if it doesn't work, then too bad.

The justification behind allowing broad regulation of commercial speech is that such regulation is required for a smoothly operating economy, and that, in fact, not regulating such speech causes actual harm.

Additionally, concepts such as Trademark, Copyright, and Patents deal with specific types of Commercial speech which are explicitly allowed to be regulated.

For non-commercial speech (often referred to as Political speech), there is a very high bar placed for government restriction, as the principle in force is that a free exchange of ideas is essential for a thriving democratic government. In general, in order for government to restrict such speech, it must:

1. Be an immediate incitement to violence (e.g. telling a group you are speaking in front of to "go burn any god-hating people's church down")
2. Be Obscene (which is horribly hard to define, but generally taken to be speech which has no redeeming societal value)
3. Immediately foreseeable to cause harm (e.g. yelling "fire" in a crowded room when there is no fire)
4. When exercising your right to speech directly infringes on another's protected rights (e.g. a sign on a restaurant which states "We don't serve Negros")
5. Matters of Libel, Defamation, and Slander
6. In specific cases concerning National Security; however, there are exceptions around where divulging National Security secrets is deemed "In the Public Good" and thus cannot be regulated. This is more of a defense against accusations of security violations than a nullification of the National Security restrictions.

In most cases, the government's ability to restrict political speech can be summed up in a single phrase: "your right to free speech ends at my nose", which can be taken as that speech is protected up until it causes immediate harm to another.