A Taipei mayoral campaign stop turned into a fight over online harassment after a teenager asked candidate Puma Shen to sign a school award certificate she had defaced — bad news for the student, who was quickly doxxed.

• Shen, the DPP's Taipei mayoral candidate, was campaigning through a market in Taipei's Zhongshan district when a high school student handed him a junior-high award certificate with Hsinchu Mayor Ann Kao's signature crossed out.
• The student said she scratched out Kao's name because of the corruption and thesis controversies around her, and wanted the certificate to be something she actually liked.
• Within four hours, blue-camp chat groups were spreading a meme accusing her of overacting, along with her name and school — blurred, but still readable.
• The doxxing revived worries about a repeat of an earlier online mobbing incident, and sparked debate over whether altering a certificate carries legal risk.
• Shen said campaigns should not suppress free speech or creativity, and urged people not to attack each other over it.

Outlook: Expect the harassment angle, not the certificate, to drive the next few days of the Taipei mayoral race.