Online privacy will remain a thorny issue over the next decade, without a widely accepted system that balances user rights and personal data collection, a survey of experts showed Thursday.

"The vast majority of experts agree that people who operate online are living in an unprecedented condition of ubiquitous surveillance," said Lee Rainie, a co-author of the report and director of the Pew Research Internet Project.

Rainie said that the experts polled see no consensus on a "trusted privacy infrastructure" and see privacy eroding as more personal information is shared online.

"People online share details about themselves in order to enrich friendships, find or grow communities and act as economic agents, and personal data are the raw material of the knowledge economy," he said.

In the survey, some 2,500 technology experts and analysts were asked whether they expect "a secure, popularly accepted and trusted privacy-rights infrastructure" by 2025. Fifty-five percent said no and 45 percent said yes.

Some of the experts said the backlash over online data collection and surveillance may lead to new privacy protections.

"Some said a backlash against privacy invasions in people's digital lives will inspire the structuring of a new equilibrium between consumers, governments and businesses and more-savvy citizens will get better at hiding things they don't want others to see," Rainie noted.

But the majority said they see privacy remaining a hot-button issue.

"Many said it is not possible to create an effective privacy rights system," said Janna Anderson, director of Elon University's Imagining the Internet Center.

"They said governments and industry have very little incentive to reverse the already quite-invasive status quo while they have much to gain from ongoing losses of civil rights in regard to individual privacy and data ownership. Some wrote that the 'genie is already out of the bottle' and said people will continue to accept subversion of privacy as an inevitable fact of life."

Danah Boyd, a research scientist for Microsoft, said, "I expect that the dynamics of security and privacy are going to be a bloody mess for the next decade, mired in ugly politics and corporate greed."

Leah Lievrouw, University of California-Los Angeles professor, said that data collection is "at the heart of the business models of the most successful technology firms" and increasingly, in traditional industries like retail, health care, entertainment and media, finance, and insurance.

Mark Rotenberg, president of the Electronic Privacy Information Center (EPIC), said he sees more privacy battles ahead.

"Within 10 years, there will be much more contentious battles over the control of identity, mobility, communications and private life," he wrote.

"The appropriation of personal facts for commercial value -- an issue that began to emerge this year with Google and Facebook's sponsored stories -- are a small glimpse of what lies ahead."

The report is part of a series of surveys of experts about the future of the Internet over the next decade.