Even though face masks cover a significant part of the face, we found that our participants identified familiar faces in masks with around 90% accuracy – no worse than the results for faces wearing sunglasses, and only slightly worse than unconcealed faces.
https://theconversation.com/why-we-can-still-recognise-people-in-face-masks-159667
So even if IncognitoGuy had a mask on as a different person, using the same logic with face masks, people can still recognise BritishMormon as IncognitoGuy