People whose sexual identity, sexual orientation or gender expression differs from the norm are vulnerable to oppression and marginalization to differing degrees in all nations of the world. In some situations they face or have faced legal sanctions up to and including capital punishment for identifying or behaving as non-heterosexual. Even when not considered illegal, same-sex attraction or sexual activity (even among consenting adults) or appearance or behavior that differs from the gender norm of a society is often stigmatized as a result of institutionalized homophobia or heterosexism. The latter half of the twentieth century has seen the emergence of a worldwide “liberation” movement seeking to eradicate systemic and cultural barriers to equal rights and to promote social inclusion for lesbian, gay, bisexual, transgender and intersex (LGBTI) people. Social workers support this effort at empowerment in each national and cultural context in which they work.