Happening now:

"Pilots who do not adhere to the following [procedure] may be intercepted, detained and interview by law enforcement or security personnel," the FAA wrote in a Sunday announcement, adding that such pilots may face deadly force in the air.

A US F-22 fighter jet shot down another object yesterday over the Canadian Yukon, and the military shut down airspace over Montana last night due to another anomaly.

UPDATE: The FAA has canceled the "national defense airspace" nearly as quickly as they declared it:

The Federal Aviation Administration has abruptly canceled a "national defense airspace" over part of Lake Michigan, the organization announced Sunday.

The FAA has not clarified why it initially banned civilian air traffic from the area earlier Sunday only to open up the airspace hours later. The FAA last established a national defense airspace over Montana this weekend in reaction to an unidentified flying object.