This is definitely a defensive move against Tencent, who is using Wechat as their weapon for global penetration. Tencent must be seen as a threat, given their ability to monetize their userbase drastically better than Facebook or Twitter. There are rumors that Tencent is also a covert investor in Snapchat as well.

GGV Partner and China VC Hans Tung makes the argument that Tencent's market cap will overtake Facebook's in 3-5 years. http://www.bloomberg.com/video/could-chinese-competition-bea...