Facebook will alert users to successful attempts by governments to compromise accounts, the social network's chief security officer announced in a low-key statement on the website.
Alex Stamos informed users on 17 October that "we will notify you if we believe your account has been targeted or compromised by an attacker suspected of working on behalf of a nation-state".
Although companies such as Google have already introduced similar notifications, this is the first time Facebook will be warning its users of attempts by governments or terrorists to hack into their account.
Stamos said Facebook decided to introduce the notifications in the wake of "more advanced" attacks around the world. "We do this because these types of attacks tend to be more advanced and dangerous than others," he said, "and we strongly encourage affected people to take the actions necessary to secure all of their online accounts."
This is the notice Facebook users will see if their account is compromised.
The news comes as Britain’s intelligence agencies could explicitly be allowed under statute to hack into phones and laptops. According to The Times, the investigatory powers bill, to be debated next month, would give Britain's spies the ability to take control of citizens' personal devices to get access to information.
Currently intelligence agencies are able to legally access metadata, which can consist of email addresses, subjects, location, and websites accessed. Some civil liberties groups said that this is already an infringement of privacy.
But according to Home Office sources who spoke to The Times, spies will soon be allowed to use software to take control of electronic devices. They will be able to extract information and use the cameras and microphones to secretly take pictures and record conversations.
It is unclear whether Facebook would be able to notify users if it detected that an individual's account was compromised in this way.