They were in Greeley Square Park. All the one-way traffic on 6th Avenue was northbound. A guy was casually riding south on his bike. Laura said, "Look at that moron. He's going the wrong way. He could cause an accident. Where are the cops?" Roger said, "Soon, we will all be 'the cops.' I've invented something. Watch." He pointed a tiny device at the cyclist. He said, "A spoken message envelops him. I'll turn up the volume really loud." Laura heard, "You're going the wrong way, stupid. Turn around." The cyclist stopped. The message kept repeating itself. He finally turned around. The message stopped. Laura laughed. She said, "That's fantastic!" Roger said, "I can produce any kind of message for any purpose." Laura said, "You can make millions from that." Roger said, "I know. But first, I've got to figure out a way that people can't use it on me!"