No harm can be attributed to homosexuality that is not equally attributable to heterosexuality.
However, there is clear and egregious harm done to homosexuals on a continuous basis both by outright bigotry, as well as the milder prohibitive stance taken by some conservative Christians. I differentiate between these two because I have made such a point through this series of taking moral discernment seriously. Just as a lynch mob and a racial slur made in a comedy club are on different planes morally, it is true that those attempting to exclude homosexuals from ordained ministry and the boys who murdered Matthew Shepard are not committing equal crimes. Intense conflict tends to push our rhetoric into hyperbole which is not helpful.
Bigotry against homosexuals is real in our society. Attend any middle-school in our country. Pay attention to which insults bear the most weight. Observe what behaviors get young boys ostracized and beat up. Our children are acting out what they see in their parents. I guarantee you that kids aren't getting mocked with such biting slurs as "mainline Christian," or "disciple of Jesus." Certainly no kid cried himself to sleep at night because his peers had called his mother a "Presbyterian".
I shouldn't make it a joke. Violent crimes are frequently targeted against homosexuals in this country. It isn't a laughing matter.
Against violence I suppose misplaced religious intolerance is preferable. Don't get the idea that a gentle "love the sinner, hate the sin" approach is anything but disingenuous, though. By coating hatred in sugary rhetoric, the anti-gay side of the church applies a respectable veneer to discrimination and legitimizes an immoral status quo. They are, despite their protestations to the contrary, guilty of enabling the violence of cruder members of society against homosexuals by perpetuating lies. They are false witnesses, a type of sinner about whom the Bible has much to say.