Don't be fooled by the jolly beard and the twinkle in his eye.

Privacy experts are taking aim at Old Saint Nick just hours before his sleigh is expected to arrive in the United States, arguing that Santa's big data operation poses a potential risk to the personal data of millions — if not billions — of parents and children around the world.

"Clearly, somebody who knows if everyone has been bad or good, and what their interests are, and can be in so many places at once, and keeps all-observing eye on everything, is somebody to be watched," said Jeffrey Chester, the executive director of the Center for Digital Democracy.

It makes sense. The North Pole is the perfect listening post. Santa lives in a remote, easily defensible location. He collects countless letters from children who spill their guts to him about their hopes and desires. He knows which presents the parents have already bought for their kids, meaning he has access to vast troves of data from retailers both online and off. All this data is likely stored in massive servers that, by virtue of being in the Arctic, are efficiently cooled at little to no cost. (Facebook has tried the same thing.)

Although Congress and the Federal Trade Commission have actively scrutinized commercial data brokers that buy and trade consumers' information, so far no lawmakers or regulators have publicly discussed Santa — possibly the biggest data broker of them all.

"Santa is able to collect a lot of information without even having to pry," said Chester, "because people are constantly writing him letters."

Chester speculated that Santa may even be working for the National Security Agency. Father Christmas, Chester said, would serve as an ideal frontman for an organization battered by the press over its surveillance programs.

"It'd be a wise invetment for the NSA to bring him on," said Chester. "After all, Santa does need a job 11 months out of the year."

Santa already has an existing relationship with the U.S. military; NORAD is currently tracking him as he flies around the world. Historical records show the NSA built a series of near-North Pole installations about 500 kilometers from Santa's workshop.

The NSA didn't immediately respond to a request for comment. A spokes-elf for The North Pole declined to comment.