本报告延续上一篇针对微信朋友圈图片过滤技术的研究，分析微信如何在聊天功能中实现实时图片过滤。微信是中国腾讯控股有限公司旗下的即时通讯应用，目前是中国最受欢迎的聊天软件之一，也是全球排名第四的最流行聊天软件。朋友圈是微信上最常用的功能之一，其中图片是用户最期望看到的内容分享形式。

In this work, we study how Tencent implements image filtering on WeChat. We found that Tencent implements realtime, automatic censorship of chat images on WeChat based on what text is in an image and based on an image’s visual similarity to those on a blacklist. Tencent facilitates this realtime filtering by maintaining a hash index of MD5 hashes of sensitive image files.

This report was collaboratively written by researchers from computer science, political science, criminology, law, and journalism studies. As befits their expertise, the report is divided into several parts, with each focusing on specific aspects of the consumer spyware ecosystem, which includes: technical elements associated stalkerware applications, stalkerware companies’ marketing activities and public policies, and these companies’ compliance with Canadian federal commercial privacy legislation.

In the days leading up to the 30th anniversary of June 4 1989, YY, a popular live streaming platform in mainland China, updated its keyword blacklists with content focused on Democracy Movement related memorials and activism in Hong Kong.

本报告从技术层面分析微信如何过滤图片，并提出可能的反审查方法。

This report demonstrates the technical underpinnings of how WeChat image censorship operates and suggests possible evasion strategies.

South Korea requires minors to have content filtering apps installed on their phones. A security audit of two child monitoring apps published by major Korean telecoms —KT Olleh Kidsafe and Clean Mobile Plus—finds serious security and privacy issues that put children at risk.

加拿大多倫多大學公民實驗室（Citizen Lab）研究表明微信從一年多前就開始屏蔽與“十九大”有關的關鍵詞，隨著十九大日期逼近，該關鍵詞庫也在不斷更新。關鍵詞涵蓋內容非常廣泛，不僅包括了批評性言論，許多對中央政策和黨意識形態的中性指稱也被過濾。

加拿大多伦多大学公民实验室（Citizen Lab）研究表明微信从一年多前就开始屏蔽与“十九大”有关的关键词，随着十九大日期逼近，该关键词库也在不断更新。关键词涵盖内容非常广泛，不仅包括了批评性言论，许多对中央政策和党意识形态的中性指称也被过滤。

The 19th National Communist Party Congress was held from October 18-24 2017. WeChat, China’s most popular chat app, blocked a broad range of content related to the Congress.