By Richard Alleyne
Sergey Brin, who co-founded the search engine giant, said the openness of the web which has fuelled the information revolution is vanishing because of censuring by countries such as China and companies creating monopolies.
He said the principles of openness and universal access that underpinned the creation of the internet three decades ago are under greater threat than ever.
The billionaire said he and his business partner Larry Page would not have been able to create their internet giant if the web had been dominated by Facebook and Apple.
Mr Brin said he was more worried than ever before.
"It's scary," he said in an interview with the Guardian.
He said that the threat came from a combination of governments increasingly trying to control access, the entertainment industry cracking down on piracy, and the rise of "restrictive" companies such as Facebook and Apple, which tightly control access.
He said five years ago he did not believe China or any country could effectively restrict the internet for long but he had been proven wrong.
"I thought there was no way to put the genie back in the bottle, but now it seems in certain areas the genie has been put back in the bottle," he said.
He said the entertainment industry was in danger of "shooting itself in the foot" by lobbying for legislation to block sites offering pirate material.
He said that it should appreciate that people would continue to download pirated content as long as it was easier to acquire and use than legitimately obtained material, he said.
Mr Brin's criticism of Facebook is likely to be seen as controversial especially as Google is one of the most powerful web companies in the world.