In a very public move to bring facial recognition technology to the fore, Amscreen, a European outdoor advertising firm, is debuting ads using face detection this week. Called OptimEyes, the technology will let advertisers know how many people are viewing the ads – in addition to their rough age and gender. The goal is to use the technology to let advertisers see the results of their advertising spending, which has proved difficult offline. The technology will ultimately allow advertisers to tailor ads specifically to certain audiences as they walk by – though public privacy concerns still abound about the extend to which this technology records, stores, and shares data.