It took a messy school bus stabbing for China to finally do something about extreme nationalism on social media

Emmanuele Contini/NurPhoto via Getty Images

• The stabbing of a Japanese mother and her son went viral in China after a local woman died protecting them.
• Her death ignited a clash between praise for the 55-year-old and a resurgence in anti-Japan posts.
• Tech giants finally intervened in a rare rebuke, deciding that the nationalism had gone too far.

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