the entire argument surrounding 'gay rights' is centered around whether homosexuality is a born physical difference (in the brain, obviously) versus a chosen behavior. naturally, if it's a physical difference, individuals may rightfully require protection from discrimination.
funny thing is, as long as i've been around, i have become convinced that it's neither a physical difference nor a choice - but rather a childhood environmental process that causes, say, a male to be almost hypnotically drawn into the psyche of his very influential mother. it's just the nature of the developing mind to do this and it explains so much, including sometimes wildly feminine mannerisms, etc.