As Occupy Wall Street protesters marched across the Brooklyn Bridge last night, after an occasionally volatile day of protests, many gasped and cheered at an unexpected surprise: Their message was being projected back at them. Displayed prominently on the building at 375 Pearl Street, beneath a giant Verizon logo, was a scrolling chant in light: “99? / MIC CHECK! / LOOK AROUND / YOU ARE PART / OF A GLOBAL UPRISING,” and so on. Its creator, Mark Read, says the “bat signal” was conceived of as a “celebration of the birthday of Occupy Wall Street.” But how they pulled it off is the best part.