During the summer of 2019-20, while Australia suffered unprecedented bushfires across the country, false narratives regarding arson and limited backburning spread quickly on Twitter, particularly using the hashtag #ArsonEmergency. Misinformation and bot- and troll-like behaviour were detected and reported by social media researchers and the news soon reached mainstream media. This paper examines the communication and behaviour of two polarised online communities before and after news of the misinformation became public knowledge. Specifically, the Supporter community actively engaged with others to spread the hashtag, using a variety of news sources pushing the arson narrative, while the Opposer community engaged less, retweeted more, and focused its use of URLs to link to mainstream sources, debunking the narratives and exposing the anomalous behaviour. This influenced the content of the broader discussion. Bot analysis revealed the active accounts were predominantly human, but behavioural and content analysis suggests Supporters engaged in trolling, though both communities used aggressive language.

中文翻译：

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#ArsonEmergency 和澳大利亚的“黑色夏天”：社交媒体上的两极分化和错误信息

在 2019-20 年夏天，虽然澳大利亚在全国范围内遭受了前所未有的丛林大火，但关于纵火和有限回燃的虚假叙述在 Twitter 上迅速传播，尤其是使用#ArsonEmergency 标签。社交媒体研究人员发现并报告了错误信息以及类似机器人和巨魔的行为，这一消息很快就传到了主流媒体。本文考察了错误信息的新闻成为公众所知之前和之后两个两极分化的在线社区的交流和行为。具体来说，支持者社区积极与他人互动以传播标签，使用各种新闻来源推动纵火叙事，而反对者社区参与较少，转发更多，并专注于使用 URL 链接到主流来源，揭穿叙述并揭露异常行为。这影响了更广泛讨论的内容。机器人分析显示活跃账户主要是人类，但行为和内容分析表明支持者参与了拖钓，尽管两个社区都使用了攻击性的语言。