Dear Vanguard Group, T. Rowe Price, and BlackRock,

The messaging and social networking apps Tencent creates count among the most popular in the world. Yet hundreds of millions of users remain in the dark about whether the company respects their rights to freedom of expression and privacy. As major shareholders, you can tell Tencent to adopt a human rights policy and respond to our letter. Trust in Tencent in China and abroad is at stake. We urge you to demand Tencent opens up today!...