There may be reasons to turn facial recognition on. Facebook warned that Photo Review, which alerts you when someone uploads a photo of you even if you aren't tagged, also switches off if you decline or disable the Face Recognition setting. It's potentially useful if someone uploads a photo of you without consent.

The tweaks also makes the settings update clearer and lets you change them in the notice, rather than the having to visit a separate screen. All changes are applicable worldwide.

The new approach may be welcome by people concerned that Facebook was using facial recognition too aggressively. It may be too little too late, though. Facebook recently lost its bid to block a lawsuit alleging that it captured millions of users' face data for its tag permissions feature without permission, allegedly violating Illinois' Biometric Information Privacy Act. These latest changes don't address previous behavior -- Facebook could still have to compensate up to 7 million people if it loses.