The meeting takes place in a bare room in a block of flats in the centre of Gaza City. No photographs, no real names – those are the conditions.

This is the first time that a group of young Palestinian cyber-activists has agreed to meet a journalist since launching what it calls Gaza Youth's Manifesto for Change. It is an incendiary document – written with courage and furious energy – that has captivated thousands of people who have come across it online, and the young university students are visibly excited, but also scared. "Not only are our lives in danger; we are also putting our families at risk," says one of them, who calls himself Abu George.

Gaza Youth's Manifesto for Change is an extraordinary, impassioned cyber-scream in which young men and women from Gaza – where more than half the 1.5 million population is under 18 – make it clear that they've had enough. "Fuck Hamas..." begins the text. "Fuck Israel. Fuck Fatah. Fuck UN. Fuck UNWRA. Fuck USA! We, the youth in Gaza, are so fed up with Israel, Hamas, the occupation, the violations of human rights and the indifference of the international community!"

It goes on to detail the daily humiliations and frustrations that constitute everyday life in the Gaza Strip, the Palestinian slice of land that Israel and Egypt have virtually sealed off from the world since Hamas was elected to power in 2006.

"Here in Gaza we are scared of being incarcerated, interrogated, hit, tortured, bombed, killed," reads the extraordinary document. "We are afraid of living, because every single step we take has to be considered and well-thought, there are limitations everywhere, we cannot move as we want, say what we want, do what we want, sometimes we even can't think what we want because the occupation has occupied our brains and hearts so terrible that it hurts and it makes us want to shed endless tears of frustration and rage!"

The text ends with a triple demand: "We want three things. We want to be free. We want to be able to live a normal life. We want peace. Is that too much to ask?"

On Facebook, the group calls itself Gaza Youth Breaks Out. When the cyber-activists wrote the manifesto three weeks ago, they gave themselves a year to gather enough support before thinking about further steps. But their text has travelled around the world at an unexpected speed and has harvested thousands of supporters, many of them human rights activists, who say they are ready to help.

Now, the authors are dealing with the impact of a document that could be a turning point in the life of the Strip. "We did not expect this to be so big," one of them admits. Eight people – three women and five men – wrote the text. They are normal students, from the more secular elements of Gazan society. All declare themselves to be non-political and disgusted with the tensions and rivalries that divide Palestinians between Hamas, the rulers of Gaza, and Fatah, the more secular party which governs the Palestinian Authority, based in the West Bank. "Politics is bollocks, it is screwing our lives up," said one member of the group. "Politicians only care about money and about their supporters. The Israelis are the only ones benefiting from the division."

Two of the group have been detained by the Gazan authorities several times, accused among other crimes of "immoral" behaviour. They say that they have been abused in jail and claim that physical and psychological punishment is commonplace in Gaza's detention centres.

Another one obtained a scholarship to attend a workshop at an American university, but he says Israel did not issue a permit that would allow him to leave the Strip.

"We are supposed to be the engine of change in this society, but our voices are muted. In the press, at university, there is no room in our society to talk freely, out of the frame, without putting yourself and your family at risk," says one, who wants to be called Abu Yazan. He adds: "In Gaza, you feel watched at school, in the streets, everywhere. You can be thrown into jail at any time. [Hamas] will threaten you with ruining your family reputation and that would be it."

These youngsters do not represent anybody except themselves, but their call for change has resonated strongly, not only abroad but also inside Gaza. Their Facebook page already has thousands of friends – including, they say, many from the Strip.

The causes of frustration are legion. The Israeli blockade forbids Gazans to travel in and out of the Strip without a permit, which is difficult to obtain. For Gazan students who wish to study abroad, the most difficult part is not being accepted at a foreign university or getting a scholarship, but simply being able to travel.

Inside the Strip, things do not get much better. Israeli shelling which follows the launching of rockets into Israel by Palestinian militants is part of their everyday life. Power cuts and ruinous sanitary conditions are among the side-effects of the embargo suffered by Gaza's inhabitants.

With high unemployment in the Strip and little access to other job markets after graduation, many feel that they have reached a dead end. Some keep studying and accumulating degrees and foreign languages, which they learn via the internet, hoping for better days to come. Others kill their time smoking hookahs with their friends day after day. There is an increasing number who rely on drugs to cope with their conflict traumas and frustrations.

Going out, meeting friends in cafés – let alone clubs or discotheques – or attending cultural events has become an increasingly complicated task as Hamas cracks down on western "decadence".

In Gaza there are no theatres and few concerts aside from the Islamic musical performances organised by the Hamas authorities. In the places where young men and women are allowed to meet, considered an "oasis" by the less conservative youth, the police are quick to interrogate mixed couples suspected of not being married or engaged.

The "last straw" for the writers of the Gaza manifesto came a month ago, when Hamas closed Sharek, an internationally financed organisation offering training and summer activities for thousands of adolescents and young people. Sharek had also became a hang-out place for the more liberal-minded in Gaza. Human Rights Watch recently issued a statement condemning its closure. "Hamas authorities in Gaza should allow an organisation that helps children and youth to reopen, and penalise officials who have harassed its workers," it said.

According to Ihab Al Ghusain, a spokesman for the Hamas Ministry of the Interior, the problems highlighted by Gaza's disaffected youth are sometimes the result of over-zealous officials. "There are no laws prohibiting men and women sitting together in public places in Gaza," he said. "But some policemen at their own initiative interrogate the couples. Those policemen should be punished."

He says that proof of the government's commitment to Gaza's young generation is that it has declared 2011 the Year for the Youth. But the authors of the youth manifesto are unlikely to be persuaded by such symbolic initiatives. The group is currently investing most of its time and energy in debating new strategies to pursue a web-based platform for change. The new year may yet become one for the youth of the Strip, but perhaps not in the way Hamas intended.

• The caption on the photograph in this article was amended on 5 January 2011 to make it clear that it shows members of Hamas's security forces.