Hostages run to freedom from a cafe under siege at Martin Place in the central business district of Sydney. (Rob Griffith/Associated Press)

The hostage standoff in Sydney, carried out by a suspected radical Muslim refugee, has threatened to fan anti-Islam sentiment in Australia. A poll in October found that the average Australian believes that the country's Muslim population is nine times its actual size, an indicator, perhaps, of the over-inflated fears of Islamic fundamentalism in the Antipodes.

Those fears have been exacerbated by the rise in the Middle East of the militant group Islamic State, which has lured foreign fighters from Australia's Muslim communities and led to terror plots hatched on Australian soil. Muslim groups in the country earlier called on Prime Minister Tony Abbott to help "isolate bigots and reassure Muslims" that they're safe in their own society.

The crisis in Sydney, which appeared to near its end on Monday night after riot police stormed a luxury chocolate shop where hostages were being held under gunpoint, offered a welcome moment for unity. Earlier in the day, as the hostage-taker remained holed up in the establishment, a stirring, inspirational hashtag proliferated across the country. "#Illridewithyou" was meant as a mark of solidarity with Australian Muslims and others, such as Sikhs, who may worry that they will be targeted because of their religious garb. It was sparked by reports on social media of some Australians comforting others who were fearful of reprisal.

The hashtag soon emerged, linked to Twitter user @sirtessa:

From there, the hashtag took off and has been shared on Twitter almost 200,000 times in the past day.

It's a welcome moment in an otherwise tense context. The British-American stand-up comic John Oliver last year pilloried Australians for living in the "most comfortably racist country" in the world, suggesting that casual bigotry toward immigrants, Muslims and non-Muslims, was rife. But many others defend the success of Australian multiculturalism. A social-experiment video earlier this year staged a confrontation between a man and a woman clad in a hijab, a head covering. The repeated scenes of other Australians coming to her defense sent the video viral on YouTube, leading to more than a million hits.

Of course, there are some critics in Australia and elsewhere who decry the "political correctness" of the #Illridewithyou hashtag. But for its creator, who has been bombarded by media requests for comments since she first spawned the meme, it's something far more simple and real.