Discourse is the exchange of ideas. It takes place between people, governments, and companies, and it can take almost any form and occur via any medium. Without discourse, societies do not exist in a basic sense: one universally begets the other.
Most societies have a cluster of core ideas that are most common at the center of a wide-ranging field of possible variations. When ideas from the outside of the graph make their way into conversations held in the center, there is often some strife, but this strife is incidental to the adjustment of the graph as a whole and is neither avoidable nor a reason to avoid discourse. While in some cases harm arises from the introduction or discussion of non-center ideas, up to and including death, these dangers are actually the result of attempts to limit discourse, and not a feature of discourse itself. So, it's really limiting discourse that bears the responsibility of discourse-related danger.
Limiting permissible ideas within a discourse is often a goal pursued by repressive agents of government or other social organizations. A "right to speech" is a key feature of the modern concept of democracy, although in practice many elements of discourse are still prohibited or limited by every such society. In fact, the limiting of discourse is such an indelible element of power structures that some prominent thinkers define discourse as the permitted conversation, not just as any conversation—the boundaries of permissible ideas define the discourse, and the agents defining the boundaries are the power structure that controls the society. Every discourse has a society, every society has power, and every person is engaged in a discourse; together, these interconnected conversations comprise an aggregate discourse that represents humanity as a whole and implies the shape of the powers that together govern humanity.
You can find discourse in a book, online, in art, in politics, and in advertising. It's everywhere.
Because discourse is a fundamental element of society, we consider it not dangerous in the sense that it is not any more possible to generalize the dangers inherent to the existence of society in the first place than it is to avoid discourse as a participant in a society.
