The inventor of the world wide web has warned that "a growing tide of surveillance and censorship" threatens the future of democracy, as more people now use the internet and social media to "expose wrongdoing".
Sir Tim Berners-Lee, who launched the web on Christmas Day 1990, said some governments were "threatened" by this, and said "bold steps" were needed.
Speaking ahead of an event where a global league table classifying countries which put the web to work best was announced, the 58-year-old computer scientist said: "One of the most encouraging findings of this year's Web Index is how the web and social media are increasingly spurring people to organise, take action and try to expose wrongdoing in every region of the world.
"But some governments are threatened by this, and a growing tide of surveillance and censorship now threatens the future of democracy.
"Bold steps are needed now to protect our fundamental rights to privacy and freedom of opinion and association online."
Sweden topped the Web Index league table launched by the World Wide Web Foundation, followed by Norway in second, UK in third and the US in fourth.
Web innovators, experts and policymakers, including Sir Tim and Jimmy Wales, were gathering in London today to assess the World Wide Web Foundation's independent annual measure of the web's impact.
The UK, despite falling down on privacy rights, was placed third overall in the Index, propelled by its high scores on availability of relevant content and political impact.
The US, the best performer in 2013 on use of the web for social, political, environmental and economic empowerment through the web, received mediocre scores on internet access, communications infrastructure, and lack of adequate safeguards to protect users' privacy from extensive electronic surveillance.
The Web Index Report revealed that beyond the digital divide, the world faces a growing participation divide, as unequal access to knowledge and speech online denies millions the necessary tools for free and informed participation in democracy.
Wealthier groups in most countries were increasingly using the web and social media to gain knowledge and amplify their voice in public debate, the research suggested.
But groups such as low-paid workers, smallholder farmers, and women in the developing world were much less likely to be able to access vital information online.
Democratisation of information and communication flows was further constrained by a global trend towards greater online censorship and surveillance, the report warned.
Along with many other countries including the UK and US, Sweden's leading record in web innovation could be at risk from excessive state surveillance.
Among the emerging nations, Mexico achieved the highest overall position in the Web Index 2013, followed by Colombia, Brazil, Costa Rica and South Africa.
The Philippines was the developing country that achieved the highest overall ranking in the Web Index 2013, with high scores on web use and measurements of people using the internet and social networks compared to other developing countries.
However, except for Morocco (ranked 54th overall in the Index), none of the developing countries in the Web Index achieved the UN World Summit on the Information Society target of connecting at least 50% of their populations, and in Africa, fewer than one in five people were using the internet.
Anne Jellema, CEO of the World Wide Web Foundation, said: "Ten years after world leaders committed to harnessing technology to build an inclusive information society, parents in 48% of countries can't use the web to compare school performance and budgets, women in over 60% of countries can't use the web to help them make informed choices about their bodies, and over half the population in developing countries can't use the web at all.
"Countries should accelerate action to make the web affordable, accessible and relevant to all groups in society, as they promised at the World Summit on the Information Society in 2003."