Virtual private networks (VPNs) are being presented as "the best tool" for journalists challenged by online surveillance by government and data collection by ISPs.

Marty Kamden, chief marketing officer of vendor NordVPN says the self-censorship that results brings about the biggest threat to online freedom and free speech: "We see a steady rise of people using VPNs around the globe.

"When governments pass strict surveillance laws, such as the Investigatory Powers Bill in the UK, or give ISPs the right to collect and sell user data without permission, as in the US, we see sharp spikes in user inquiries.

"People are starting to realise that they need to take action to protect their online privacy, and a VPN is the best tool for that."

VPNs encrypt a user's data and reroute it through a secure tunnel before accessing the internet, protecting sensitive information by hiding an IP address.

Kamden says the existence of "surveillance states" breeds fear and conformity, and doesn't allow free expression, as found by an Oxford study, conducted last year. "Four years have now passed since Edward Snowden's revelations about global mass surveillance, which is led by American NSA, in coordination with intelligence agencies in the 'five eyes' alliance from the UK, Canada, New Zealand and Australia.

This month, the Council of Europe has announced that 28 out of 47 member states do not sufficiently protect journalists against violence and threats, resulting in self-censorship amongst journalists.

More than half the journalists surveyed said they had been subjected to intimidation by government; four out of ten reported being threatened with physical violence; one in four said they had been belittled and humiliated by management; and more than one in five said they had been arrested, investigated, prosecuted or threatened with prosecution.

As a result, more than 30 per cent of the journalists said they had toned down sensitive stories, and 15 per cent confirmed they completely abandoned these stories. One in five journalists said they shaped their reporting to suit their company's political or business interests.

"Online surveillance by government and data collection by ISPs in many countries result in self-censorship online that brings about the biggest threat to online freedom and free speech," says Kamden.