Poseiden, a computer-based vision system from VisionIQ recently detected a suspiciously still girl at the bottom of a 12-foot-deep Welsh pool and alerted lifeguards, who proceeded to save her from drowning (). (In the hurly-burly of the crowded pool, the lifeguards had missed seeing the stationary form.)
After many years of slow, painstaking, and (frankly) unimpressive progress, computer vision systems seem to have reached some kind of explosive inflection point. Poseiden is a particularly impressive example of the breed, handling as it does a huge number of moving (and stationary, when something goes wrong) objects and widely-varying light- and shadow levels.
This is good and bad news.
The good news is that we're clearly much closer to systems that can scan a crowd and identify faces. The bad news is that...we're clearly much closer to systems that can scan a crowd and identify faces.
Imagine a huge database of time-stamped faces tied to identities and locations. What's the harm in that? A skilled hacker (or corrupt clerk) could query for married people who frequently go out to restaurants with a non-spouse. Or people who visit drug-dealing neighborhoods in which they do not live. With a little more research, bang: high-quality blackmail material. So a few years from now, the penalty for certain kinds of questionable/illegal behavior may rise dramatically. But don't worry, there's something you can do to protect yourself. Just remember the words of Josef Stalin: "The innocent have nothing to fear."