A tip for all of you aspiring investigative reporters: When you expose an Internet sex hoax, there are going to be consequences. Take it from me. My sleuthing got me an unplanned role in a piece of erotic fiction that starred Chewbacca as a Wookiee Casanova. It all started on the weekend of July 4, when I spotted a discussion on the Web site Metafilter about a new fad called "greenlighting." The dubious claim was that an "emerging underground [group] of sexually promiscuous teenagers" had started wearing green shirts with the collar popped up. When a greenlighter spotted a fellow traveler, he yanked his or her collar down, triggering anonymous sexual escapades. (What's it called when you wave off a green-shirted lothario? Redlighting, of course.)The amazing part is the upbeat attitude that the article displays.