WhatsApp has been criticised over its handling of user data

WhatsApp has been criticised by a prominent pressure group over the way it handles user data.

The Electronic Foundation (EFF) gave the wildly popular messaging app a "one star" rating in its annual "Who Has Your Back?" report examining how tech companies respond to government demands for information on their users.

WhatsApp, which has more than 800 million monthly users, was jointly tied for last place with telecoms company AT&T, behind other low-scoring companies including Verizon, Google, Comcast, and Amazon.

Included for the first time in the annual report, the EFF says that "although [we] gave the company a full year to prepare for its inclusion in the report, it has adopted none of the best practices we've identified as part of this report. We appreciate the steps that WhatsApp's parent company Facebook has taken to stand by its users, but there is room for WhatsApp to improve."

Specific issues identified by the EFF include:

• "WhatsApp does not publicly require a warrant before giving content to law enforcement."
• "WhatsApp does not publish a transparency report or a law enforcement guide."
• "WhatsApp does not promise to provide advance notice to users about government data demands."
• "WhatsApp does not publish information about its data retention policies, including retention of IP addresses and deleted content."

That said, WhatsApp has taken a strong stance on encryption, implementing strong end-to-end encryption ensuring that messages on the platform cannot be intercepted and read by hackers or law enforcement - even with a warrant. Founder Jan Koum grew up in Ukraine during the Soviet era, and has since become a vocal advocate of user privacy.

"Nobody should have the right to eavesdrop, or you become a totalitarian state," Koum told Wired in 2014 - "the kind of state I escaped as a kid to come to this country where you have democracy and freedom of speech. Our goal is to protect it. We have encryption between our client and our server. We don't save any messages on our servers, we don't store your chat history. They're all on your phone."

Apparently, however, this rhetoric wasn't sufficient to merit a higher score from the EFF. In contrast, eight companies were awarded five stars this year - Adobe, Apple, Credo Mobile, Dropbox, Sonic.net, Wikimedia, Wordpress.com, and Yahoo. The report commends the eight companies for their "strong user rights, transparency, and privacy."

Business Insider has reached out to WhatsApp for comment and will update this story when it responds.

Here's the full scorecard: