https://www.reuters.com/article/us-tencent-toutiao-lawsuit/tencent-sues-toutiao-for-alleged-defamation-demands-1-yuan-and-apology-idUSKCN1IX4MB >Chinese social media giant Tencent Holdings on Friday said it is suing two companies under domestic rival Toutiao for alleged defamation, escalating its growing feud with the firm behind what is currently the world's most downloaded iPhone app.