Human rights campaigner Bianca Jagger will tell a Belfast crowd this evening (Friday) that social media websites like Twitter can help drive a worldwide human rights revolution.

But she also issued a warning that political leaders will increasingly want to impose internet censorship to block social change:

The Nicaraguan-born campaigner is in Belfast to deliver the Amnesty International Annual Lecture as part of Belfast Festival at Queen's.

In her lecture she is expected to say:

'In 1970, Gil Scott Heron said, The revolution will be televised.

'Not any more. Today, the revolution will be Tweeted. The protests taking place today are being orchestrated and recorded on the internet, and through social media. If people want a revolution, they connect on Facebook and Twitter to arrange one.

'The events of this year in the Middle East and North Africa demonstrate why regimes there have so much to fear from social networking.

'One of the reasons that social media has been effective in the Middle East, and in Tunisia in particular, is because over half of the population are under 25 years old. These young people have mobile phones, they Facebook, Tweet and share ideas. Today's youth are more than aware that these social networks can facilitate dialogue, and bring about change.'

'It should come as no surprise that in areas of the world where human rights are most violated, the strongest forms of internet censorship exist.

'Even within the most hard-line and previously secure regimes, leaders are now finding themselves threatened by social networking. Indeed oppressive governments are realizing what power for effective political change the internet can yield.

'Social media are a tool with the potential to revolutionize the human rights movement. However, they are also extremely vulnerable, to censorship and interference. And these attempts to censor social networking sites may not be restricted to oppressive regimes, or dictatorships.'

The Amnesty International Annual Lecture takes place on Friday at 7:30pm in the Elmwood Hall as part of Belfast Festival at Queen's. Some tickets available at the door.