Facebook has started rolling out an update to its photo tagging system that will now scan newly uploaded photos and alert all the users it recognizes in that image by default. The new system works by scanning each image users upload on the site, looking for human faces. Facebook will use the same facial recognition scanner to detect people not tagged in an image and inform the user who’s in the photo. The system will roll out to all countries except Canada and the EU, where the company has not deployed its photo-tagging mechanism.
Source: https://www.bleepingcomputer.com/news/technology/facebook-will-alert-you-when-someone-else-uploads-a-photo-of-you/