It would be difficult to come up with a better illustration of the profound effect data can have on people's lives than the Ashley Madison hack, which has not only sparked numerous lawsuits but also been associated with several suicides.
On Tuesday, many of the world's experts in computer science and mathematics spent an afternoon at the Heidelberg Laureate Forum in Germany trying to figure out how the widespread collection of data about consumers can be prevented from causing more harm in the future.
"In the U.S., there are now states where jail sentencing guidelines are being set by data," said Jeremy Gillula, a staff technologist with the Electronic Frontier Foundation. "Data has a huge impact on people's lives, and that's only going to increase."
Much of today's data collection happens on the websites people visit, and it's done both by the websites themselves and by the advertising networks that power them. That, in turn, can spill over into surveillance by governments as well, Gillula said, such as when organizations like the National Security Agency tap Internet backbones.
Such data can be used to choose the ads you see, the prices you pay for services like auto insurance and the opportunities you have, but how those decisions are made typically isn't clear.
"We are living in a black box society," said Ciro Cattuto, scientific director and head of the Data Science Laboratory at the ISI Foundation. Algorithmic "black boxes" are used to make countless important decisions about people's lives, but "you don't know how they work or what the algorithm is," he said.
Compounding the problem is the fact that the data amassed isn't always accurate or complete. In addition, it may give far more away than consumers realize.
"We're not just revealing our likes and dislikes but also our psychological traits -- cognitive biases that could be used to influence us," noted Alessandro Acquisti, a professor from Carnegie Mellon University. "We're sharing the 'buttons' that others can use to push us in a certain direction."
With the help of such data, what's currently known as targeted advertising will become much more, Acquisti explained. "It will no longer focus so much on matching products with consumers, but on using personal information to change the advertising message on the fly so it speaks directly to you," he said.
For example, it would be easy for any advertiser to learn from a consumer's Facebook page who his girlfriend is, Acquisti pointed out. Using the girlfriend's image to promote a product might be too much, but it's not difficult to imagine that the advertiser could "morph" her face with that of a product spokesperson, thereby making the target consumer more likely to respond positively to the ad, he said.
There's a need for better mechanisms for protecting individuals' privacy, most participants agreed, as well as for more transparency on the part of those collecting and using the data.
What form that transparency should take, however, isn't entirely clear. If proprietary algorithms were simply published, for instance, would the average consumer even be able to interpret them?
"The technology is too complicated for humans to understand," Acquisti said. "We need a policy approach" that offers not just privacy by design, but privacy by default, he said.
Public policy and legislation are one approach to the problem, but some don't see much reason for optimism in that direction.
"The policy solution in the U.S. has failed," the EFF's Gillula said. "We have no hope there, which is why we're switching to technical solutions."
The group has already published a "Do Not Track" policy that companies can embrace, for example. It's also working on Privacy Badger, a browser extension for Firefox and Chrome that blocks spying ads and invisible trackers.
The EFF advocates end-to-end encryption as well. "Agencies can't do mass surveillance if all the data is encrypted," Gillula pointed out.
If nothing else, it's clear that the solution to the problem can't come from just one side.
"No one community can solve the problem by themselves," Cattuto said.
That it's a problem, however, seems to be beyond dispute.
As Turing Award winner and "father of the Internet" Vinton Cerf said, "We need to pay a lot of attention to this."