Facebook announced this week it would begin focusing on private messaging services, on top of its public social media post model.

In a blog post Wednesday, the Menlo Park, California-based company's chief executive officer, Mark Zuckerberg, said one of Facebook's new principles would be encryption. He said end-to-end encryption on all of the company's messaging services—WhatsApp, Facebook and Instagram—is “the right thing to do.”

“At the same time, there are real safety concerns to address before we can implement end-to-end encryption across all of our messaging services,” he wrote. “Encryption is a powerful tool for privacy, but that includes the privacy of people doing bad things.”

He's touching on an ongoing debate that, so far, doesn't have an easy answer.

“I think the biggest debate that has raged about implementing encryption into social media is how do you respond to law enforcement requests [for] the data?” said Wynter Deagle, a partner at Troutman Sanders.

Encrypting messages can prevent data breaches and keep communication secure. It can also prove troublesome for law enforcement, who require a specially built “backdoor” to access encrypted messages that could help an investigation or prevent crime.

In the U.S., platforms are not required by law to include a backdoor for law enforcement, though other countries, namely Australia, have passed bills requiring companies provide access during investigations.

“One of the challenges from a security standpoint is if you create a backdoor, that backdoor could also be potentially used by hackers, people with bad intent. It creates a way into your encrypted systems,” said Thomas Barnett, special counsel and chief of data science, analysis and investigation at Paul Hastings.

He noted that offering users encryption with a backdoor option may provide a false sense of security. If a breach happens, the company's reputation is on the line. Some users may also feel less secure knowing that their messages can be accessed, a further public relations problem, Deagle noted.

It's also complicated to implement backdoor access on a global scale. Platforms then have to answer: Who does the door open for? Under what circumstances, and in what countries? In his blog post, Zuckerberg said political dissidents told him “encryption is the reason they are free, or even alive.”

“If you make an exception for the U.S. government, are you going to make value judgments around which governments are trustworthy enough to provide the backdoor to?” Deagle said.

Last year, Australia passed a bill requiring companies operating in the country provide an encryption backdoor to law enforcement. Outside of Australia, most countries don't yet have an encryption law, though lawyers noted that the encryption debate is happening alongside a growing number of privacy legislation worldwide.

The European Union's General Data Protection Regulation and other privacy laws could require companies to update users if they make encryption changes. But, lawyers said, it's not yet clear if there's an obligation for tech companies to use encryption under privacy laws.

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