GREAT LAKES, FREE-FIRE ZONE. The Coast Guard would like to practice terrorist-interdiction techniques on the Great Lakes. Perhaps that's evidence somebody's serious.

Lake Michigan has been used for military training in the past, going back to World War II. In recent years, parts of the lake have been designated as training zones, including areas near the Great Lakes Naval Station and Fort Sheridan, north of Chicago, and areas off of Manitowoc and Sheboygan counties that have been used occasionally for Air National Guard training.