Leave it to Japan to create Billboards that use facial recognition software to identify gender, ethnicity and age of whoever approaches. I guess this makes us one step closer to a Minority Report/Blade Runner future...
The purpose of this tech in the future will be for advertisers to single out passerby's, fit them within a category and then verbally call them out on what they need.... i.e. A GAP billboard calling out to a 20 something yr. old to remind them to buy new jeans.
Whether you like this or not, or believe billboards like this may cross the lines of privacy issues... Japan is currently public testing these as we speak.