Facebook users will be notified every time your face is uploaded to the platform, even if it is not marked.
The new face detection function does not apply to users in the European Union or Canada, where the data protection Supervisory authorities have prevented the use of this technology.
The social network said the new option is “empowering” users.
But critics expressed concern about how open Facebook in any other way, that the data you collect.
“We want people to feel safe, if you have pictures of yourself on Facebook, so we will begin soon, with facial recognition technology so people know when someone uploads a photo of you as your profile picture,” Facebook said in a statement.
Ailidh Callander, legal officer at Privacy International, said: “It’s really important, from a privacy perspective, Facebook users understand and control what happens with your data.
“Facebook privacy settings can be complex to understand, and there is still a lot we don’t know how Facebook processes personal data of users and non-users – for example, information about your contacts.
“The progressive end-of-life use of face recognition technology in the day-to-day, whether in social media or public spaces, is increasing at a rapid pace and has both legal and ethical implications.
“It can have unintended consequences and, in the case of Facebook, RSS-feeds in your ever-growing profiling capacity.”
The news comes as Facebook faces fresh observation by the European regulatory authorities, including a case in Germany, opened a new front in the fight against the dominance of large technology companies.
In a novel use of competition law, Germany’s anti-trust regulator Facebook accused of, that she their power as the dominant social network to push the user in so that it to collect data about you from third party sources, such as web pages with the “like” Button.
Meanwhile, in France, Facebook-owned WhatsApp has been ordered to share user data with Facebook without your consent.
The algorithms that power Facebook-facial-recognition-technology – the analysis of the pixels in the photos – are extremely complex, not least because of the huge amounts of data, you have to learn””.
Facebook has the technology since 2010, when the company began offering suggestions for the day in a photo.
For the new feature, the Facebook a template, the face of a person by the analysis of pixels from the existing photos and the comparison with newly uploaded images.
Users who do not wish to participate, you can decide in your privacy settings.