Brisbane woman Rachael Jacobs' gesture sparked the #illridewithyou social media movement. Confession time. In my Facebook status, I editorialised. She wasn't sitting next to me. She was a bit away, towards the other end of the carriage. Like most people she had been looking at her phone, then slowly started to unpin her scarf. Tears sprang to my eyes and I was struck by feelings of anger, sadness and bitterness. It was in this mindset that I punched the first status update into my phone, hoping my friends would take a moment to think about the victims of the siege who were not in the cafe. I spent the rest of the journey staring – rudely – at the back of her uncovered head. I wanted to talk to her, but had no idea what to say. Anything that came to mind seemed tokenistic and patronising. She might not even be Muslim or she could have just been warm! Besides, I was in the "quiet carriage" where even conversation is banned. By sheer fluke, we got off at the same station, and some part of me decided saying something would be a good thing. Rather than quiz her about her choice of clothing, I thought if I simply offered to walk her to her destination, it might help.

It's hard to describe the moment when humans, and complete strangers, have a conversation with no words. I wanted to tell her I was sorry for so many things – for overstepping the mark, for making assumptions about a complete stranger and for belonging to a culture where racism was part of her everyday experience. But none of those words came out, and our near silent encounter was over in a moment. My second status was written as a heartbreaking postscript to my first. While the woman appeared to appreciate my gesture, we had both left defeated and deflated. What good is one small action against an avalanche of ignorance? Hours later, social media showed me good people can create their own avalanche of kindness. The movement has inspired thousands to publicly and loudly stand up for a decent and humane world

My posts were written on my private Facebook page to a private audience, never intended for public eyes. A friend of mine made his own decision to share it publicly, and I'm deeply humbled by his action. Perhaps the story was then shared widely because it represented what so many people felt in their heart. But while I'm warmed by the sheer volume of media interest, I am not the story here, and my actions were not extraordinary or heroic. We are all in shock at the tragedy that has unfolded, and out of respect for the victims' families, I'm reluctant to take any media focus. I've made the decision to decline interviews for a few reasons. I have spent some time in the public eye due to my recent experiences as a candidate in federal and local elections. I would be mortified if anyone thought I was using this tragedy for political gain. I'm also a teacher and lecturer and have a responsibility to represent my profession and institution. At a time of heightened emotions, a misplaced word or phrase could cause offence, requiring numerous explanations and reassurances. But most importantly, my role in this movement was minuscule and unworthy of the attention received. The #illridewithyou hashtag, started by Twitter user @sirtessa and embraced by thousands, is the real story of inspiration. The movement has inspired thousands to publicly and loudly stand up for a decent and humane world. It's a pre-emptive strike against racism and bigotry. We know what fear can do to a society, and rather than fall victim, thousands have pledged to be part of the force that fights for tolerance and compassion.

As we grapple with the tragic end to the siege, there's no better time to ride with each other, walk with each other, listen to each other or just silently be there for someone else. Our grief as a nation will be overwhelming and we will be confounded as we try to make sense of this event. It will be tempting to search for answers in politics or beliefs, sheltering in the irrational fear that more madness is to come. But #illridewithyou reminds us that we can overcome fear and ignorance with a pledge to treat each other with respect. It's a reminder that decent Australians don't hold an entire group of people responsible for the actions of one man. Some claim the movement is patronising, forcing misplaced support upon those who need space, rather than spotlight. They may have a point. But there's no doubting its good intentions. And perhaps we need it more for ourselves as a reminder that there are reasoned and tolerant people that walk among us, publicly disempowering the trolls. One of the most common questions I've been asked is "Do you have a message for the Muslim community?"

In truth, I don't. They are a strong community with their own articulate leaders, able to speak for themselves if they choose to do so. I am, however, the daughter of Indian migrants, and having lived all of my 37 years in Australia, I feel I've seen the best and the worst this country has to offer. I'd rather deliver a message to racists, bigots and anyone who dares to derive a message of hate from this tragedy – it is you who are unwelcome here. Your values have no place in civilised society, and if you spread intolerance, there's an avalanche of kindness ready to take you down. Rachael Jacobs is a lecturer in Education at the Australia Catholic University in Brisbane. She was the Greens candidate for the seat of Brisbane in 2013. Full coverage: Sydney siege ends: live updates

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