The intelligence community has talked about using open-source data for years, but a George Mason University doctoral candidate and his cohorts are taking the concept to the next level. The Wall Street Journal last week reported that Curtis Melvin and about a dozen other “citizen snoops” — some of whom are former military analysts — have spent the last two years using Google Earth’s satellite images to map out the infrastructure of North Korea. It’s not easy, since North Korea is perhaps the most secretive country on the planet. Melvin and others sift through news reports, photographs and eyewitness accounts,…