Tim Berners-Lee, who launched the Web in 1990, made the remarks as he released his World Wide Web Foundation's annual report tracking the Web's impact and global censorship. The index ranked Sweden first in Web access, openness and freedom, followed by Norway, the U.K. and the United States.
"One of the most encouraging findings of this year's Web Index is how the Web and social media are increasingly spurring people to organize, take action and try to expose wrongdoing in every region of the world," said Berners-Lee, 58.
"But some governments are threatened by this, and a growing tide of surveillance and censorship now threatens the future of democracy," he said, adding that steps need to be taken to protect privacy rights and ensure users can continue to gather and speak out freely online.
The report said online spying and blocking are on the rise around the world, and politically sensitive Web content is blocked in almost one in three countries. It also said that most countries surveyed have failed to use the Web to properly disseminate basic information on health and education.
Despite their high overall rankings, the U.S. and Britain both received mediocre scores for safeguarding users' privacy. Mexico was the highest ranking emerging economy at 30th. Russia came 41st, China was at 57th, and Mali, Ethiopia and Yemen were at the bottom of the list.
About 39 percent of the global population was online in 2013 - more than double from 2005, which recorded 16 percent. In Africa, fewer than one in five people are using the Internet, with many saying they cannot afford it.