Already deployed. Here's a report by a retailer who installed a face recognition system.[1] Names anonymized.

“We now know within seconds of a person walking in the store if they’ve previously been caught stealing from us. ... Suppose Johnny Johnson is caught shoplifting at a Store-Mart branch. He’s detained, photographed, and given a barring notice. Johnson’s photo is entered into Store-Mart’s database of known shoplifters, becoming an “enrollee” in the system. Three weeks later, Johnson walks into Store-Mart again. Within five seconds, the system has captured his image from the store security cameras, compared it against every photo enrolled in Store-Mart’s database, found a match, and sent an alert to the in-store loss prevention associate’s (LPA) smartphone. The LPA looks at his phone, and Johnson’s name, photo, and detention history with Store-Mart pops up. The LPA verifies that the photo in the alert actually matches the person who just walked in. Then the associate approaches and says, “Mr. Johnson, you’ve previously been given a barring notice from Store-Mart. You’re not allowed to be here. Please leave.” And Johnson walks back out. So, within a minute or so of walking in, a known shoplifter has left the store, empty-handed."

Coming next, the sharing model:

"A national shoplifter database similar to the Stores Mutual Association model is already in the works. This would mean that each additional retailer who adopts the security camera technology and starts sharing will incrementally increase the value of the system for all members."

[1] http://losspreventionmedia.com/insider/retail-security/facia...