Wikipedia Reference Information
Hate speech is a controversial term for speech intended to degrade, intimidate, or incite violence or prejudicial action against a person or group of people based on their race, gender, age, ethnicity, nationality, religion, sexual orientation, gender identity, disability, language ability, moral or political views, socioeconomic class, occupation or appearance (such as height, weight, and hair color). The term covers written as well as oral communication and some forms of behaviors in a public setting. It is also sometimes called antilocution and is the first point on Allport's scale which measures prejudice in a society.
However, the term is also used as a form of censorship of non-politically correct opinions.
The complete, up-to-date and editable article about Hate Speech can be found at Wikipedia: Hate Speech