Web inventor Sir Tim Berners-Lee has created a technology he says will give people more control over their data.
Called Solid, the technology puts personal information in one place so people can decide what is shared with which service or site.
Sir Tim said Solid was needed because the current model of handing over lots of data to many different online services did not serve people well.
Solid has been set up as an open source project to which anyone can contribute.
In addition, Sir Tim has created a company called Inrupt to build Solid's basic infrastructure.
"The web has evolved into an engine of inequity and division, swayed by powerful forces who use it for their own agendas," wrote Sir Tim, on a blog on the Medium website.
Solid would restore balance to the web because it meant people never lost control of their data, he said.
"People want apps that help them do what they want and need to do - without spying on them," wrote Sir Tim.
"Apps that don't have an ulterior motive of distracting them with propositions to buy this or that."
Solid involves secure silos called pods into which people deposit data such as contact information, images and video.
This data always remains in its pod and online services would request access to it rather than expect it to be lodged on their sites and servers.
The pods could be thought of as a secure USB stick or personal website, Sir Tim said, and it was up to users to decide to whom to give access to the different types of data they were storing.
People could have more than one pod for different purposes or types of data, he said.
"With Solid, you will have far more personal agency over data - you decide which apps can access it," Sir Tim said.
Gathering data into one silo should also make it easier for apps to analyse it and deliver benefits to individuals, he said.
Solid could help to make the web closer to the way it was originally envisioned, said Sir Tim.
But tech journalist and commentator Bryan Lunduke is sceptical about Solid's chances, saying the technology is "overblown".
And identity and privacy researcher Steve Wilson asked: "Even if people could control their personal data, what does Solid do about all the data created about us behind our backs?
"Do we know what proportion of personal data is generated without the individual's involvement?"
Sir Tim is taking a sabbatical from his work at the Massachusetts Institute of Technology and a step back from involvement in the World Wide Web Consortium to free more time to develop Solid.
Inrupt is now looking for app developers and other online services to adopt Solid and start doing more serious tests of the idea.