Life sized virtual doubles

In an effort to speed up security clearance at Manchester Airport from next week they are using full sized holograms of staff to prepare travellers as they enter the security zone (see story here). The idea seems to be that passengers are more likely to take notice of a person than a tannoy announcement or a television screen and the virtual self takes some of the work away from their real counterparts. The holograms are realistic enough that some passengers are fooled into trying to hand them their travel documents. I'm sure there are all kinds of plots that could be linked to such holograms, with witnesses being fooled into seeing a hologram rather than the real person, thus providing an alibi, etc. Kind of like virtual twins. If it works, it'll be interesting to see if the world starts to be populated with very helpful virtual doubles.