The term ‘hate speech’ is vague, broad, and in practice, everyone defines it differently. This confusion tends to lead to expansive understandings of hate speech which, in practice, can jeopardize freedom of speech. Indeed, laws against hate speech or hateful speech are often misused to punish and silence journalists, dissenters, and minorities, recently in countries as varied as Hungary, India, Rwanda, Kazakhstan, and Bahrain. We focus instead on dangerous speech since it is a narrower, more specific category, and we define it by its link to something that almost everyone can agree on (unlike the definition of hate speech): violence against a group of people is a grave harm that should be prevented. Also dangerous speech can be quite different from hate speech: sometimes it doesn’t even express hate, and instead promotes fear. Definitions of hate speech differ, both in law and in colloquial use, and some aspects of the term remain undefined. For instance, what is hatred? How strong or how durable must emotion be to count as hatred? Another unresolved question is this: does the ‘hate’ in hate speech mean that the person speaking feels hate, or wants to convince someone else to hate, or wants to make someone feel hated in response to the speech? Generally, ‘hate speech’ refers to a message that vilifies a person or group of people, because they belong to a group or share an identity of some kind. Legal definitions of hate speech refer to various kinds of groups, defined by religion, race, or ethnicity; others add or omit disability, sexual orientation, gender, or even philosophy of life (Norwegian Penal Code, section 135a). Under all of those definitions, then, “I hate you” is not hate speech. In practice, the boundaries of hate speech are drawn by prevailing social norms and individual and collective interpretation, so that each person has an idea about what hate speech is, but one person’s notion of hate speech rarely matches another’s. Focusing instead on the narrower category of dangerous speech makes it easier to achieve consensus, and to respond effectively. For some examples of debate on what constitutes ‘hate speech’ see this article on the French newspaper Charlie Hebdo’s cartoons and text, and this New York Times report on students who felt that “Vote Trump 2016,” when written in chalk on their campus’ steps, was hate speech. And here is a thoughtful discussion on hate speech by the British writer Kenan Malik, who argues that hate speech should be morally condemned but not criminalized.