Tech company Turn said it would stop using tracking cookies that are impossible to delete. The decision came in response to a ProPublica article this week that revealed the controversial practice.
"We have heard the concerns and are actively re-evaluating this method," Max Ochoa, Turn's chief privacy officer, wrote in a blog post.
He said the company plans aims to suspend the practice by "early February."
Turn's zombie cookie was exploiting a hidden undeletable number that Verizon uses to track its customers on their smartphones on tablets. Turn used the Verizon number to respawn tracking cookies that users had deleted. The company said it will now re-evaluate its practices.
Turn's decision to suspend the practice was a sharp reversal from its previous stance. It had previously argued that "clearing cookies is not a reliable way for a user to express their desire not to receive tailored advertising."
Critics across the Web vocally disagreed. Jason Kint, CEO of a trade association for digital content companies, wrote that "this kind of surreptitious behavior does nothing to build trust between consumers, advertisers and publishers." The Electronic Frontier Foundation, a digital rights organization, said Turn's action made it " impossible for customers to meaningfully control their online privacy."