Homophobia
Homophobia is defined as "irrational fear of, aversion to, or discrimination against homosexuality or homosexuals." Homosexuality, whether believed to be an inherent quality that one is born with or a lifestyle choice, elicits strong emotions in some individuals. This reaction can be driven by fear, uncertainty, ignorance, or – as the definition states – it is very often merely irrational. Homophobia is an aversion that affects people of the LGBT (Lesbian, Gay, Bisexual, Transgender/Transexual) community in many ways by restricting their rights (Proposition 8) or denying opportunity based on sexual preference.
The emotional effects of homophobia are extremely damaging. While growing up, children are very impressionable and are influenced by almost everything around them: friends, family, television, celebrities, etc. At school, stereotypes that are perpetuated by peers can cause considerable damage to a developing young person. A young individual who is questioning their sexuality can feel threatened, disgusted, or fearful of himself or herself because of the homophobia perpetuated on the playground. Terms like "faggot," "gay," "homo" are substituted all too frequently for words like "lame," "stupid," or "dumb." Boys who do not play football or basketball, or do not participate in stereotypical gender role assigned behaviors are often criticized and called girly or a wimp. It's this association that perpetuates the hate that fuels homophobia. If not stopped at an early age, this behavior and mentality continue and often get worse with age.
Homophobia during adolescence often started in childhood. High school aged individuals and older are often set in their beliefs and mind set. If their homophobia is strong enough, violence may be the next logical step in their mind to retaliate against the feared homosexuals. Hate crimes are directly related to severe cases of homophobia, and show that homophobia is still prevalent in our country today. One of the most prominent hate crimes of our time is the case of Matthew Shepard, who was an openly gay college student attending the University of Wyoming. He was tied to the side of the road, severely beaten, and left for dead in 1998. His aggressors attacked him because they felt that Shepard had made sexual advances on them and their reaction was violence towards the supposed homosexual acts. This hate crime is still viewed today as a prime example of the extent that homophobia is instilled in today's culture.
Despite laws protecting the rights and safety of LGBT people, the law often still has a base on some type of homophobia. 
Sodomy laws are very problematic because they put restrictions on certain sexual behaviors. There are certain laws regarding oral sex and/or anal intercourse which are directly associated with some of the choices of homosexual males. There are also certain laws banning gay men from donating blood due to the AIDS outbreak; these laws were put in place in the late 1980's but are still in effect despite our medical progression. Homophobia in law enforcement dates back to before the origin of the gay rights movement with the Stonewall riots, which are an iconic moment in the history of the LGBT community. The Stonewall riots were in response to a police raid on a gay bar and in the Greenwich Village neighborhood of New York City back in 1969. The raids of gay bars were common, but the police in this specific raid lost control of the situation and fights and racketeering ensued. America was still very homophobic in nature, but this specific riot gave gays and lesbians in the community confidence to stand up for themselves and fight for equality and their rights.
The existence of homophobia is damaging and threatening to those affected. Gays of all ages feel the presence of homophobia, no matter whether it's on the playground, in school, on television, or reflected in the law. The gay rights movement has continued to do a lot to move our country in a positive direction while trying to erase the hate. But a change as big as this takes time. Everyone can do something, big or small, to help eradicate homophobia from our society. Help change the hate.
http://www.merriam-webster.com/dictionary/homophobia