Facebook is taking a cue from Google and Apple and giving its users more encryption options, despite FBI criticism that locking user data could place lives in danger by limiting government surveillance.

The social network this week announced it would allow users to encrypt notifications sent from the site to their email addresses, protecting potentially sensitive emails, such as a request for a new password, from hackers, spies or anybody who does not have the user’s private key. Among those excluded from access to the private key: Facebook itself, which is used by 935 million people on an average day.

Users can go to the “About” page on their Facebook profiles to add a public key created by the Open PGP protocol – PGP is an acronym for “pretty good privacy” – and decrypt email messages using a corresponding private key. People can also share public keys with others in order to have an encrypted chat on a different messaging service.

“It's very important to us that the people who use Facebook feel safe and can trust that their connection to Facebook is secure,” the social media company said in a blog post. The contents of messages and other activity on Facebook itself would not be encrypted, but the move adds a layer of privacy to the site.

It also means that people who activate the email encryption and then lose their private key cannot turn to Facebook for help, says Jay Nancarrow, a communications manager with Facebook. The social network would have a copy of the public key uploaded to a user's Facebook profile, but encrypted chats or emails off the site would still require the users’ private key to unlock, he says.

Users may have other options to unlock messages if they've lost their key. "Other account recovery methods like SMS and Trusted Contacts can still work without relying upon email recovery," he explains. ​​​​​​​​​​​​

Facebook’s plan comes as the U.S. government struggles with surveillance legislation and online privacy. Apple and Google last year boosted user privacy by eliminating their abilities to remotely unlock smart phones and access data stored locally on those devices. The moves sparked criticism from the FBI, because it meant the companies could not access private phone data even if compelled to do so by an order from the Foreign Intelligence Surveillance Court.

The FBI declined to comment to U.S. News,​ but referred to testimony given in April during a House hearing by Amy Hess, executive assistant director of the FBI’s Science and Technology Branch.

"Law enforcement and national security investigators need to be able to access communications and information to obtain the evidence necessary to prevent crime and bring criminals to justice in a court of law,” she told the House Oversight and Government Reform Committee’s Subcommittee on Information Technology. “But increasingly, even armed with a court order based on probable cause, we are too often unable to access potential evidence.”

Sen. Rand Paul of Kentucky, who is vying for the GOP presidential nomination, previously told U.S. News that he supported the encryption efforts by Google and Apple, saying, “there is a right to privacy and the government needs to stay out.”

The Committee to Protect Journalists on Monday praised Facebook’s encryption decision and pointed out that sharing public encryption keys online could help reporters communicate with sources about controversial topics.

"Facebook has taken an important step to help protect users' private communications by default, and make the risky environment in which journalists work a little bit safer,” the advocacy group wrote in a blog post.

It's unlikely that Facebook or Google will give users the chance to encrypt chat that take place on their own servers to protect it from access by the company or by a court order, says cryptologist Bruce Schneier, a fellow at Harvard University's Berkman Center for Internet and Society.