FINDING · DETECTION
WeChat, Alibaba Wangwang, Zhihu, and Sina Weibo all implement keyword combination filtering — messages are blocked only when every component of a blacklisted combination appears simultaneously, regardless of order. This allows censors to target sensitive contexts (e.g., 习近平 + 三连任 [Xi Jinping + three consecutive terms]) without filtering neutral mentions of individual terms.
From 2019-xiong-efficient — An Efficient Method to Determine which Combination of Keywords Triggered Automatic Filtering of a Message · §3 · 2019 · Free and Open Communications on the Internet
Implications
- Circumvention tools that relay user content (e.g., mirrors, paraphrase services) must account for multi-term combination triggers, not just single-keyword blocklists — splitting or paraphrasing one component of a sensitive combination may be sufficient to bypass filtering.
- When building corpus measurement pipelines for Chinese platforms, treat each platform's keyword ruleset as independent; the paper found little consistency across services.
Tags
Extracted by claude-sonnet-4-6 — review before relying.