At the same time, Dozier adds, taking on Xiaonei wouldn't be easy.

FORBES: Facebook's Clone Problem

Compared with StudiVZ, Xiaonei has the potential to grab far more users.

FORBES: Facebook's Clone Problem

By taking on StudiVZ, Facebook may be trying to start small, building a legal precedent before it takes on Xiaonei or other, bigger copycats.

FORBES: Facebook's Clone Problem

Xing Wang, the creator of Xiaonei which Renren acquired and built into its social networking house, is now running a GroupOn-type model in China, Meituan.

FORBES: Serial Entrepreneurs Set Up Shop in China

Xiaonei, whose name means "in the school" in Mandarin, claims to have attracted around 15 million unique visitors last April, compared with StudiVZ's 6 million registered users.

FORBES: Facebook's Clone Problem

Examples include Zhihu, a Quora-like service for China, and Diandian, a Tumblr-like blog hosting platform for China, started by high-profile Internet entrepreneur Jack Xu, notably the former CIO at XiaoNei (now Renren).

FORBES: Just How Hot Is China Venture? Very!

Facebook and was previously called Xiaonei.com.

FORBES: Renren Rides China's Social Networking And Gaming To $3.20

Xiaonei closely mimics Palo Alto, Calif.

FORBES: Facebook's Clone Problem

When Charles Zhang, the founder of Chinese portal Sohu, bought ChinaRen in 2000, Xu stayed on for a few more years until 2005 when he rejoined Chen at Oak Pacific Interactive and worked on the social networking site Chen acquired in 2006, Xiaonei, later renamed Renren.

FORBES: Chinese Tech Star Jack Xu Looks To PaPa For His Next Hit