Anti-LGBT rhetoric and anti-gay slogans are themes, catchphrases , and slogans that have been used against homosexuality or other non-heterosexual sexual orientations and to demean lesbian , gay , bisexual , and transgender ( LGBT ) people. They range from the demeaning and pejorative to those expressing negativity on religious , medical, or moral grounds and some characterize it as being hate speech.
Though the psychiatric establishment once medicalized same-sex desire, homosexuality was later removed in 1974 as a mental disorder from the Diagnostic and Statistical Manual of Mental Disorders (DSM) because it wasn't supported by sound scientific evidence and didn't meet the criteria for a mental disorder.   There has been significant controversy over this decision.  However, according to another rebuttal of this argument, held by, among others, The American Society for the Defense of Tradition, Family and Property , there are some behaviors exhibited by many animals that most would consider unnatural in humans, such as cannibalism.  The counter argument to this claim is that it confuses "unnatural" with "wrong," and that this is therefore simply a restatement of the claim that homosexuality is morally wrong (like cannibalism), not unnatural.  These issues are complicated by the polysemous character of the terms "natural" and "unnatural" which can be used in many equivocal ways.