Far rightwing figureheads immediately invented an elaborate and racist conspiracy theory that CNN had lightened a photo of alleged Fort Lauderdale airport shooter Esteban Santiago shortly after the Friday attack. In reality, CNN had yet to air a picture of Santiago, let alone lightened a picture of him. The conspiracy also used a picture of an entirely different man named Esteban Santiago—not the alleged shooter. Still, writers at websites like InfoWars and Gateway Pundit tweeted about CNN’s nonexistent Photoshop job. Former Republican Florida Congressman Allen West, who represented Fort Lauderdale itself, even tweeted about the conspiracy and linked to an...