International government leaders have called for a more open and secure internet at the fourth annual Freedom Online Coalition conference, being held in the Estonian capital, Tallinn, this week.

Thanks to modern technologies and the internet, "we become more and more vulnerable," said Estonian president Toomas Hendrik Ilves in the opening session of the conference.

“Everything can be known and in some cases, everything is known.”

Ilves, who learned to code as a teenager, said Estonia —which along with Georgia, suffered damaging denial of service attacks in 2007 believed to have originated with Russian state hackers — particularly understood the need for a free and open internet.

“The rights that people have offline must also be protected online,” he said.

Giorgi Margvelashvili, the president of Georgia, also said an open internet, with a focus on security and privacy, was essential.

“I come from a country which suffered an attack … especially in the area of the internet.” he said in his opening address.

“We share the fundamental value that the individual has the right given by birth to express himself … and that societies are created through this freedom of expression. Governments don’t have the right to limit those freedoms, but should increase the security for those expressions.”

However, the Dutch foreign minister Frans Timmermans noted that democratic governments had suffered a blow to their credibility following revelations of widespread surveillance by whistle blower Edward Snowden.

“Recent events —Snowden, et cetera —have challenged our credibility as free countries to handle the internet in a way our citizens will accept. Our credibility has been undermined and we need to regain that credibility.”

This would require a free and open discussion of such issues, he said.

Not just governments, but businesses, which increasingly gather, store and analyse user data, must also enter such a conversation, argued several politicians in the session.

"The private sector has to play an important part," said John Baird, Canada's foreign minister.

Ilves said: “Big data knows and can deduce more about you than Big Brother ever could.”

In a taped address to the conference, UN Secretary-General Ban Ki-moon expressed support for the Coalition’s goals.

“Freedom is a timeless value,” he said, noting that all UN member countries have expressed a commitment to protecting freedom “on paper, but in practice, it is different.”

He said he was “disturbed” by some countries’ attempts to control internet access.

He also said that while at times, access to digital data was needed to battle crime, surveillance should always be “narrowly focused” and have a proper legal mandate.

The Freedom Online Coalition is an intergovernmental coalition of 23 member countries, with the stated purpose of advancing Internet freedom.