Amsterdam airport security might be a little high-strung, but one can't criticize their efforts to keep their passengers safe even in the face of some of the most eccentric threats we've ever seen. Amsterdam's Schiphol airport had to deal with two such threats today: a bomb from WWII and a plane hijacking that didn't even really happen.
First off, Schiphol's Terminal C and part of Terminal D were shut down after construction workers found something strange buried under C. It was an unexploded bomb from WWII. According to Reuters, the 1,100-pound German bomb has been buried underground these past 70 years because Schiphol used to serve as a military airport and was bombed by Nazi Germany during the war. According to the AP, the Nazis eventually seized control of the airport, and then the Allies bombed it as well, though this little souvenir managed to hibernate intact.
The discovery of the WWII bomb caused the cancellation of some flights.
Another threat that took Schiphol off their schedule: There were reports that a plane was hijacked en route from Malaga, Spain to Schiphol, but the reports ended up being completely false. The Dutch media reported that the plane was being escorted back to the airport by a pair of F16 fighter jets, but the Spanish airline Vueling tweeted an explanation for it afterwards (translation courtesy of AP):
"Amsterdam's protocol for security was activated owing to a temporary loss of communication between the plane and air traffic control."
Great day to fly the international skies, eh?