Cookies and IP addresses can still be linked back to you, even if you switch devices, Wilson said.
Some industries are easier to fool than others. Airlines, for instance, have a publicly available clearinghouse of tickets' "true" prices, called Sabre, Wilson said. And rental car agencies often sort search results into a matrix of very specific options and packages which would be difficult to personalize.
Still, there's research left to be done on how deep personalized price discrimination goes, Wilson said.
"They could infer that I'm a liberal and they might only send me news searches with New York Times and MSNBC. That's arguably bad for me, shielding me from opposing viewpoints. That's a specific example with unforeseen negative consequences," he said.
"Predictive policing, surge pricing, we don't know how those systems work, or what data is being used. That's potentially concerning. ... Marketplace effects are easy to quantify, but there are other more negative areas, moral and ethical."