Santa 'tracked by missile system'
As well as watching for a nuclear missile attack, America's air defence body is tracking Santa's Christmas Eve flight for the 55th year.
Now the information is on Twitter, Facebook and mobile phones as well as the traditional phone line and website.
The North American Aerospace Defence Command will not say exactly how Santa's route gets on to its computer screens, but the updates are popular around the world.
Last year, the Santa Tracks NORAD website had more than 13 million unique visitors and the phone line got more than 74,000 calls.
This year, Santa Tracks NORAD has nearly 450,000 "likes" on Facebook and nearly 28,000 followers on Twitter.
It takes four months of planning and 1,200 volunteers to stage the event at NORAD headquarters at Peterson Air Force Base, Colorado.