Hate the idea of impersonal cameras ticketing you for running a red light or driving 36 mph in a 25 mph zone? The antidote might be in a red aerosol can. A Harrisburg, Pa., company sells a spray to stop camera-generated tickets by making your license plates so reflective it blinds the spying cameras when their flash goes off. Tests show that "Photo Blocker," a product sold over the Internet by Phantom Plate, can help drivers beat traffic-enforcement camera tickets by coating their license plates with a spray. Phantom Plate started selling the product three years ago. The company...