Social media brings hope and frustration for Chinese activists at home and in exile

Since the dawn of the information age, it has become clear that social media can be a powerful force for social change.

From Tunisia to Taiwan, new technology has been key to organising protest movements and motivating people - especially the young - to get involved.

But for those pressing for change in mainland China, attempting to harness social media poses challenges, and not just because Beijing is well aware of the power of social media and draws "red lines" that internet firms and users cannot cross.

Many exiled dissidents are from the era of typewriters and attempting to adapt to the new technological landscape has been challenging; many have elected not to learn the "language" of the internet.

"I even can't contact some of them via e-mail," said Dr Yang Jianli, a veteran activist now living in the US state of Virginia.

Activists among the Chinese diaspora have long debated their role in advancing democracy in China, and within a broadly defined movement that includes exiles, faith-based groups and dissidents turned academics, there is no single platform to unite them.