As soon as news broke that the San Bernardino, Calif., shooters were Muslim, skilled Muslim activists took to social media platforms to denounce Syed Rizwan Farook, 28, and his 27-year-old wife Tashfeen Malik. But after the New York Post’s online headline “Muslim Killers: Terror eyed as couple slaughters 14 in Calif.,” the term “Muslim Killers” began trending with more than 10,000 tweets.