I... think it's a terrible idea... simply due to... how it's going to further complicate headphones, and make the general public lazier... not to mention the potential for privacy invasion.
Before creeps had to work to figure out who you are, now they just look at you with their phones say some words to their phone and BAM there's your face book... I just really dislike the entire concept, ofc on the positive side it will aid those who are vision im paired which is a nice thing, still as a pro I see them assisting those who cannot see
as a con... I see a lot of legality issues coming into play and the over all laziness of people today increasing!