Sometimes, protesters prove their opponents' point. In Canada last month, a dozen masked men wearing military camouflage burst into a Christian meeting at a Calgary, Alberta, hotel. They beat sticks together, hoisted signs, and roared slogans, drowning out a speech by Rev. Tristan Emmanuel on "Christophobia" and the actions taken against Christians for their unpopular views on homosexuality. "Haters!" screamed the self-proclaimed "Gay Militia" into the faces of men and women who had been meeting peacefully. "Bigots! ... What you are doing is a hate crime!" The raucous invasion lasted 10 to 15 minutes, said Jim Blake, regional director of...