Well yes it used to happen before - but not now if you are wearing Google Glass with InSight app.
This Google part-funded app, that was unveiled at the HotMobile technology conference in Jekyll Island, Georgia, last week, aims to help users find their friends and be spotted themselves in busy places like shopping centres, sports stadia and airports.
Face recognition systems cannot be used for this, says InSight developer Srihari Nelakuditi at the University of South Carolina in Columbia, because it is unlikely someone in a crowd will be looking straight at a headset's camera.
So Nelakuditi joined forces with Romit Roy Choudhury and colleagues at Duke University in Durham, North Carolina, to develop a recognition system based on a "fashion fingerprint" of a person's outfit, from their clothes to their jewellery, badges and glasses.
This fingerprint is constructed by a smartphone app which snaps a series of photos of the user as they read web pages, emails or tweets. It then creates a file – called a spatiogram – that captures the spatial distribution of colours, textures and patterns (vertical or horizontal stripes, say) of the clothes they are wearing.
This combination of colour, texture and pattern analysis makes someone easier to identify at odd viewing angles or over long distances.
Read more about it at: New Scientist