Amazon has quietly removed encryption from its Fire tablets

Amazon has quietly dropped support for disk encryption on its Fire tablets, saying the feature that secures devices by scrambling data was not popular with customers.

Privacy advocates and some users criticized the move, which came to light on Thursday even as Apple was waging an unprecedented legal battle over U.S. government demands that the iPhone maker help unlock an encrypted phone used by San Bernardino shooter Rizwan Farook.

On-device encryption scrambles data on a device so that it can be accessed only if the user enters the correct password. This helps secure users' data against hackers, or if the device is lost or stolen.

The Guardian reports that the change isn't mentioned in public materials Amazon has put out about the update.

Cryptologist Bruce Schneier said Amazon's move to remove the feature was "stupid" and called on the company to restore it. "Hopefully the market will tell them to do otherwise," he said.

Amazon is publicly supporting Apple in the iPhone case. On Thursday, it - along with Facebook, Google, Microsoft, and other tech companies - filed an amicus brief asking a federal judge to overturn the court order requiring Apple to create software tools to unlock Farook's phone. The brief said the companies "are also fully united in their view that the government's order to Apple exceeds the bounds of existing law and, when applied more broadly, will harm Americans' security in the long run."

Apple's legal battle with the FBI has thrust encryption and cybersecurity onto the US national agenda during an election year, divided public opinion, and pitted the might of the US Justice Department against one of the world's most powerful companies.

Amazon spokeswoman Robin Handaly said in an email that the company had removed the encryption feature for Fire tablets in the fall when it launched Fire OS 5, a new version of its tablet operating system.

"It was a feature few customers were actually using," she said. (Handaly also told Wired that "all Fire tablets' communication with Amazon's cloud meet our high standards for privacy and security, including appropriate use of encryption.")

Digital privacy advocates said that was not a good reason for discontinuing the feature.

"Removing device encryption due to lack of customer use is an incredibly poor excuse for weakening the security of those customers that did use the feature," said Jeremy Gillula, staff technologist with the Electronic Frontier Foundation.

"Given that the information stored on a tablet can be just as sensitive as that stored on a phone or on a computer, Amazon should instead be pushing to make device encryption the default - not removing it," Gillula said.

(Editing by Stephen R. Trousdale and David Gregorio)

Disclosure: Jeff Bezos is an investor in Business Insider through hispersonal investment company Bezos Expeditions.