Inspired by the role of social media in the Arab Spring, Palestinians have harnessed the same tools, under the wary gaze of the authorities in the West Bank and Gaza.

In both parts of the Palestinian territory, ordinary people and activists have taken to social networking to share their hopes, mobilise demonstrations and call for government reform.

Sabri Saydam, former Palestinian minister for technology, says the use of social media to bring about political change was bound to happen, given the high number of Facebook users across the territories, particularly in Gaza.

"We have one million Palestinian subscribers to Facebook in the West Bank, Gaza and east Jerusalem," he told AFP.

"Usually, people (in the region) would have been inspired by the Palestinian cause, but in 2011 things changed and the Palestinians were inspired by the Arab revolutions and started using that, even though the atmosphere and the environment were different."

Early in 2011, as the Arab uprisings were beginning, activists in the West Bank and Gaza used Facebook, Twitter and text messaging in a campaign to end the bitter split between the rival national movements, Fatah and Hamas.

Their efforts culminated in massive March 15 protests, and six weeks later the factions said they were patching up their differences and ending years of bloody rivalry, driven in no small part by the huge public protests.

Since then, new technology has played a central role in rallying the Nakba border protests on the anniversary of Israel's creation, the bid for full UN membership and the campaign to boycott products made in Jewish settlements.

Although activists already use social media to document and expose rights abuses by settlers or clashes with the Israeli army, its use for domestic political activism is more limited.

And its emerging role as a platform for everyone from the politically motivated to the spiritually disillusioned has not gone unnoticed by Gaza's Hamas rulers or by the Palestinian Authority in the West Bank.

Jillian York, director of International Freedom of Expression at the Electronic Frontier Foundation (EFF), a US-based Internet rights watchdog, says Palestinian social media face both surveillance and self-censorship.

"You have people arrested here all the time, of course, but it's really hard to know who is being surveilled," she told AFP on the sidelines of the first Palestinian social media conference in Ramallah last month.

In 2010, Walid Hassayen from the northern West Bank town of Qalqilya was arrested on charges of blasphemy, becoming perhaps the most high-profile example of a Palestinian being sanctioned for online activities.

On his Facebook page, written in the name "Allah," Hassayen allegedly poked fun at the Koran, and he also ran a blog in which he discussed religion.

He was arrested in October 2010 and sentenced to three years, raising cries of alarm from rights groups.

Last September he was released. But since then, he has rarely stepped out of the family home and now no longer goes online.

"I was accused of insulting religion and religious sentiments and of causing sectarian unrest," he told AFP by phone.

"There is nothing called freedom of speech in the Palestinian territories as I was only practising my right to freedom of expression and belief."

More recently, radio journalist George Cannawati found himself on the wrong side of the law after he criticised the government-run health authority in a posting on Facebook.

"I posted something on Facebook criticising the way the employees treated me and I was shocked to learn that Bethlehem governor Abdel Fatah Hamayel was suing me for libel, slander and defamation," he told AFP.

His posting was picked up by several Palestinian news websites, prompting the governor to take legal action, which ultimately failed on a technicality.

"They invaded my privacy and read the posting on my personal Facebook page, but I have the right to freedom of expression," he said.

In Gaza, users face an array of restrictions, including blocked pages, Israeli and Hamas surveillance and the possibility their posts will be used against them.

"The online surveillance is only a small component of what is happening," York said.

"It's very rare that somebody is only going to be targeted for something they've said online. In Palestine, it's like you're already an activist and they use something that you've said online against you."

In April 2010, 22-year-old Assad al-Saftawi was arrested by Gaza's Hamas rulers and charged with "slander" and "promoting lies inciting against the government" after he criticised them in a Facebook posting picked up by Al-Ayyam newspaper.

He was handed a six-month suspended sentence. A year later, he spent four days in detention over his role in organising the mass demonstrations of March 15.

Now he sometimes hesitates before posting, he says.

"In addition to Hamas surveillance, I also practise self-censorship to please my family which is worried about me," he told AFP. "But sometimes when you are angry, you just can't control it."

Hamas did not respond to requests from AFP to comment on the issue of online surveillance.

Saftawi says he no longer cares about being detained for speaking his mind.

"Now I am apathetic about being arrested," he said.

"If we all remain silent in the face of injustice, who is going to speak up?"