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If President-elect Donald Trump decides to make good on his campaign pledge to "load up" the prison camp in Guantanamo Bay, Cuba, with new domestic terror suspects caught in the US -- including American citizens -- legal experts say he is asking for an unprecedented constitutional showdown.

A Pope and a pop star ruled Instagram this year, but they weren't the only popular figures on the social media platform. Olympic icons, caffeinated hashtags, an Oscar-winning actor and smiley-face emojis also were crowd-pleasers. Here's what else we learned cruising through Instagram's 2016 list of the most popular hashtags, emojis, celebrities and moments:

Austrians go to the polls Sunday to pick a president, with a choice between left-wing Alexander Van der Bellen and anti-immigration candidate Norbert Hofer of the far-right Freedom Party.

His friends know him as "Mo." And he is the most unlikely ISIS recruit you will ever meet.

In picking General Jim Mattis, President-elect Donald Trump said Thursday night that he has found his "General George Patton." Yet that label may not really capture what makes Mattis a distinctive choice. Mattis has been sharply critical of President Barack Obama's policies on Iran, and Obama's capping of troop numbers and campaign end-dates in theaters of war such as Afghanistan and Iraq. Mattis also appears to be a skeptic of the Obama-era policy of putting women into combat roles.

The tragic fairy tale came to an end Friday, as members of the Cinderella soccer team killed in the crash of LaMia Flight 2933 returned home to Brazil.

Continuing with the theme that paced his campaign, President-elect Donald Trump was anything but a traditional politician on Friday, holding a phone call with the President of Taiwan.

North Korea's 32-year-old leader is often mocked online, on TV shows and in movies, but it is believed Kim Jong Un could have 50 to 100 nuclear weapons by 2020 -- a reality that should give a chill to anyone tempted to dismiss Kim as anything less than serious. Recognizing the threat, this week the UN Security Council voted unanimously to introduce new sanctions, stating that North Korea should abandon its nuclear weapons program.

President-elect Donald Trump's transition is being viewed at home as chaotic, and his move from candidate to statesman is being closely scrutinized by the global media as well, particularly his communications with world leaders.

Oh, not those kinds of pirates. Darn it.

At the beginning of this century, Teller and I made a TV show in which we traveled around the world watching street magicians. These weren't conjurers who worked for tourists, but the magicians who performed for locals. We spent the nights in fairly nice hotels, but the days we spent on the streets in real Egypt, real China and real India.

Austria's far-right Identity Movement opposes globalization and "Islamization" -- but a key figure of the group says they see themselves as patriots, not neo-Nazis.

The world as we know it could come to an end this Sunday. Or it could be just another day. It depends on whom you talk to.

Nearly 2,000 Iraqi troops were killed across Iraq in the month of November, according to newly released UN figures, as they battle to force ISIS extremists from the country.

Don't blink. You might miss another jump in oil prices.

"The year in pictures" treks across the globe, looking back on the events that shaped 2016.

President Barack Obama will sign an extension of the Iran sanctions bill passed in Congress this week, White House spokesman Eric Schultz said Friday, although he called it "not necessary."

Thousands of refugees and migrants, most fleeing violence in the Middle East, mass at the sealed-off border, chanting "Open! Open!" They are desperate to cross into Hungary, but a razor-wire fence, temporary blockade and a line of riot police stand in their way.

An iron gate with the notorious Nazi slogan "Arbeit Macht Frei" stolen from a German concentration camp site most likely has been recovered.