Hate crime

• I think I have been the victim of a homophobic / transphobic incident, what can the police do?
• Someone has attacked me because of my race, what can I do? / I have suffered from a racial incident, what can I do?
• Someone is sending me threatening / abusive / offensive messages via a social networking site. Is this a criminal offence?
• What is a hate crime or hate incident?
• What is the law on racial and religious hatred and hatred on the grounds of sexual orientation?