The United States is training thousands of cell phone and Internet pro-democracy campaigners worldwide to evade security forces in what it calls a "cat-and-mouse game" with authoritarian governments.

The US government is sponsoring efforts to help activists in Arab and other countries gain access to technology that circumvents government firewalls, secures telephone text and voice messages, and prevents attacks on websites.

"This is sort of a cat-and-mouse game and governments are constantly developing new techniques to go after critics, to go after dissenters," said Michael Posner, the assistant US secretary of state for human rights and labor.

"We are trying to stay ahead of the curve and trying to basically provide both technology, training, and diplomatic support to allow people to freely express their views."

Posner told a small group of reporters that the theme of Internet freedom will be "peppered" throughout the State Department's annual report on human rights for 194 countries that is scheduled for release on Friday.

US Secretary of State Hillary Clinton is campaigning hard for freedoms of expression, assembly and association online -- what she calls the world's town square or coffee house of the 21st century.

The chief US diplomat has said the protests in Egypt and Iran fueled by Facebook, Twitter and YouTube reflected "the power of connection technologies as an accelerant of political, social and economic change."

The US government, Posner said, has budgeted $50 million in the last two years to develop new technologies to help activists protect themselves from arrest and prosecution by authoritarian governments.

And it has organized training sessions for 5,000 activists in different parts of the world.

A session held in the Middle East about six weeks ago gathered activists from Tunisia, Egypt, Syria and Lebanon who returned to their countries with the aim of training their colleagues there.

"They went back and there's a ripple effect," Posner said.

State Department officials said one of the new technologies under development is the "panic button," which allows activists to erase contact lists on their cell phones if they are arrested.

"If you can get the panic button that wipes that (list) clean before they get locked up, you're saving lives," said Posner.

The new technology has not yet been made available to pro-democracy campaigners but it will prove useful in places like Syria, where the authorities simply go out and arrest activists who use their mobile phones.

The State Department said it has already funded efforts by private firms, mainly from the United States, to develop a dozen different technologies to circumvent government censorship firewalls.

"One of them has been very successful in Iran. It's being used extensively. and we have the download numbers," a State Department official said on condition of anonymity.

"It's going viral and now that technology is spreading all over the Middle East," said the official, who declined to name the technology in order not to endanger the people who are using it.

The State Department is also funding efforts to prevent governments from launching attacks -- known as denial of service -- aimed at shutting down websites that might publish an investigative report or other critical material.