The hostage crisis at the Lindt Chocolat Cafe in Sydney, Australia, unfolded in a way impossible a decade ago.

Much of it played out on Facebook and text messaging (already there as of 2004), and on YouTube, Twitter, and other social media as yet unborn in 2004. To be a hostage-taker or hostage as of 2014, it seems, you need good social-media skills.

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"There's an unprecedented degree of immediacy to such crises now," says Lawrence Husick, senior fellow at the Foreign Policy Research Institute and codirector for the Center for the Study of Terrorism. "All the players are so acutely aware they're being watched. It's Shakespearean: All are walking that stage."

The gunman, identified as Iranian-born self-styled sheikh Man Haron Monis, had an iPad and posted messages. Monis very self-consciously went for symbolism: He chose a site near banks, courts, and the Channel 7 television station. Knowing the eye of the world was upon him, he had hostages take turns holding up to the cafe window the "Black Standard" used by Islamist groups such as Al-Nusrah, reading, "There is no god but Allah, and Muhammad is Allah's messenger," which embodies the Muslim creed.

For their part, hostages used text messaging and Twitter, Facebook, and YouTube to get out their own messages. Later, the gunman used them as his social-media go-betweens. Hostage Marcia Mikhael posted a list of his demands on Facebook:

"1. Send an [Islamic State] flag to the cafe and someone will be released.

2. To speak with [Australian Prime Minister] Tony Abbott and 5 people will be released.

3. Media to tell the other 2 brothers not to explode the bomb. There are 2 more bombs in the city."

As of this writing, the bomb threat had not been substantiated.

One hostage text-messaged his mother: "Mum I'm in the Lindt cafe in Sydney."

"My heart stopped," the mother (name withheld) told radio station 2GB. She texted back: "What is going on? Are you okay."

"I'm okay mum, can't talk."

When cafe worker Elly Chen was among the first hostages to escape, her Facebook page hosted a flood of relief from friends and well-wishers, including Priscilla Luong: "Such a relief to see that you are safe and sound - today must've been a difficult day, hang on tight girl."

In a standoff that led to bloodshed and death, much of the preceding struggle between gunman and authorities was over media and message. At a Sunday news conference, New South Wales Police Commissioner Andrew Scipione actually spoke directly to hostages, figuring they'd be following media reports and encouraging them to urge the gunman to contact police.

Deputy Police Commissioner Catherine Burn said, "We are monitoring all forms of communication, including Facebook and Twitter, for any information that might assist." Apparently police gleaned valuable information about events inside the cafe, which may also have helped shape strategy.

Law enforcement asked news venues not to broadcast information such as the gunman's name, the number of police assembled, strategy, weapons, or tactics, both to protect the integrity of the operation and also in the (correct) belief that Honis was monitoring TV, radio, and social-media reports.

That call for cooperation got a degree of support rarely seen in Western media. "There's a certain degree of social contract remaining between media and law enforcement in Commonwealth countries," says Husick. "If government asks that they do or not do something, they give them the benefit of the doubt."

Police and local media knew Honis well (see below) but kept his identity from the world. Faces of hostages, when they could be glimpsed, were blurred out in videos. When the gunman's demands went out via hostages' Twitter feeds or Facebook posts, these were soon taken down. Same for hastily recorded videos, posted on YouTube, of hostages reciting the gunman's demands. When Honis contacted broadcaster Ray Hadley of 2GB, demanding that a hostage be allowed to speak live on air via phone, Hadley refused.

It was a rare example of one side controlling the story - in an age where usually no one can. "It definitely helped contribute," Husick says, "to the isolation and futility of the hostage-taker." That growing sense of futility may have compelled Monis to open fire in the cafe, unleashing the final police assault in which he and two hostages were killed.

Social media have long been seen as "force multipliers" - means of extending power or impact - for both terrorists and those who fight them. The so-called war on terror has also been a social-media war, as the Taliban, al-Qaeda, the Islamic State/ISIS, and other groups recruit and terrorize through websites, videos, tweets, and posts, and their opponents seek to blunt, stunt, or suppress their efforts.

In July, the Islamic State debuted its glossy Web magazine, Dabiq. A recent article called on individuals to mount lone-wolf terror strikes. On his own website, Monis (who repeatedly called himself a "peace activist") had vented his anger over Western airstrikes against Islamic State forces in Iraq and Syria. Even if he were not directly in al-Qaeda or the Islamic State, then, he may have been a jihadi by inspiration.

But it's all mixed up. He was also a man in trouble with the law, on bail on charges of being an accessory to the murder of his ex-wife (#accessory was trending high on Twitter in Australia on Monday). Last year, he was convicted of mailing letters to widows of Australian soldiers killed in Afghanistan, in which he called the soldiers "murderers." On Friday, Monis lost an appeal on those charges.

After the gunfire and stun-grenades, the ambulances and the all-clear, a humane and heartening social-media postscript also arose: the Twitter hashtag #IllRideWithYou. Fearing an anti-Muslim backlash because of the hostage crisis, people took to Twitter to voice support for Australian Muslims and offer to accompany them on public transport. You have to wonder whether something like this would ever happen in the United States.

Sarah Hay tweeted: "Australians showing how it's done. #Illridewithyou = solidarity and no to racism towards muslim community during Sydney siege." Alicia Bourke tweeted: "Perfect response as a public, showing an awesome spirit exactly true to our country."

#Illridewithyou had been used more than 260,000 times by Monday night in Australia.

215-854-4406 @jtimpane