Fading data could improve privacy
Privacy could be enhanced if data was allowed to fade, suggests research.
Dutch researcher Dr Harold van Heerde is looking into ways to gradually "degrade" the information that sites gather about visitors.
Slowly swapping details for more general information can help guard against accidental disclosure, he said.
"There are so many weak points in security that you can never be sure that your data is safe," said Dr van Heerde.
The research project carried out by Dr van Heerde from the Centre for Telematics and Information Technology (CTIT) at the University of Twente looked into ways to change the way databases manage information about users and customers.
The ability of those databases to gather information tempts companies and organisations to hoard information just in case it proves valuable, Dr van Heerde told BBC News.
The dangers of having data about us stored more or less permanently in many different places around the web have been proved many times when that information is leaked by accident or design, said Dr van Heerde.
"People make mistakes, people can be bribed," he said. "You cannot protect this data, you cannot be sure it's not been disclosed, privacy policies are simply too weak."
Instead of simply refusing to use services that gather data, Dr van Heerde believes it would be better for people to surrender data knowing that there was a policy that determined how it degraded over time.
At initial use to secure a transaction or get useful information from a search all relevant details might be stored. Subsequently details would slowly be swapped for more general information.
In the case of a location-specific search information about a user's exact GPS co-ordinates could be swapped for a street name, then a neighbourhood and then just a city.
"You can slowly replace details with a more general value," he said.
As well as limiting the impact of any disclosure, such a policy might also force companies to be more explicit about what data they gather and what they will use it for.
"In most cases there's no good reason for them storing data for so long," he said.