Hardcore Nine Inch Nails fans got a special treat last week when Trent Reznor and company hid tickets to a private concert all over Los Angeles. More than twenty question marks appeared on a Google Earth map that NIN put out on their tour page. The question marks were labeled with phrases like "Men's room. Behind the mirror. Be discreet," and "Incredibly ugly hat. Last pair of tickets." Quick-thinking fans noted the GPS coordinates of question marks and set off on a treasure hunt, much like geocachers.