With around 35,000 active websites making up the Arab 'blogosphere', internet users in the Middle East have found new forms of expression, networking, and mobilisation online.

Blogs and social media sites have now become the preferred platform for political and human rights activists, who can highlight stories that may otherwise go unreported or be censored.

In the past, media in the Middle East has simply been shut down for criticising the government, but controlling the internet has become increasingly difficult as online activity grows.

In response, many governments are focusing more on censorship, surveillance and, what critics call, intimidation towards bloggers and cyber-activists - some of whom have been arrested, harshly interrogated, and detained indefinitely.

On Thursday's episode of the Riz Khan show we ask: How much of an effect has online activism had on politics in the Middle East? And what is the gap between online rhetoric and reality?"

Riz discusses the issues with Imad Bazzi, a Lebanese blogger, and Bassem Samir, an Egyptian blogger.

You can join the conversation. Watch this episode of the Riz Khan show live on Thursday, March 18, 2010 at 2030GMT, with repeats the next day at 0030GMT, 0530GMT and 1130GMT.