The WBC has literally nothing to do with Christianity. They use the broad protection of religious practice and speech in America as a way to provoke people. And that's their business: They sue if people infringe on those rights. It's a scam, an incredibly cynical and dishonest family business. No more, no less.
Let's understand them for what they have finally become: An excuse for everyone they hate to join together in love -- Jews, Muslims, Queer people, soldiers -- damn near everyone. Even Christians, since no actual Christian could possibly live up to their standards. How could they, when their standards don't seem to exist?
So, in contrast to what Lady Gaga says, let's draw as much attention to them as we can. Let's hold them up as the gold standard for hatred, hypocrisy, greed, and just plain stupidity. Let's be inspired, by their hatred, to love. Let's hold them up as the logical conclusion of all the hate that is in the world. Let's show, through our own love and respect and tolerance, how much better the world can be without that kind of hate.
Let's just not give them any reason to sue anyone. That's what they're after. The rest, well who cares. If they want to fester in their misery, that's their problem.