The Secret Service is investigating an Internet advertisement as a potential threat against President-elect Barack Obama, but the people who created it say a technology glitch was responsible, and they feel terrible about it. Ads for a company that sells mobile-phone ring tones that appear on the Yahoo News Web site, teased viewers into taking an IQ test. But when viewers scrolled over the ad's picture of Obama, the words "When Will You Die?" flashed across the image. The Secret Service said it had known about the ad for "a couple of weeks." Yahoo, on the other hand, as well...