These anomalies are fairly common over Mexico City International. From my sources, pilots flying into MCIA that have anomalies detected by radar are usually questioned and briefed thoroughly. I don't know if this is a government or airline exercise but I know it happens. Pilots that have flown north out of MCIA into the United States have experienced some amazing accounts, especially over the state of Chihuahua into southwest Texas.
Pennsylvania continues to be an active state for reports of unusual activity. During 2009, strange incidents came to my attention that were reported by Pennsylvania residents from forty-eight counties across the state. Some of the types of unusual events reported included sightings of Unidentified Flying Objects, Bigfoot and other creature encounters, photo anomalies, strange footprints and sky flashes.