The startup Renew has outfitted recycling bins with gadgets that track smartphones.
Recycling bins in the City of London are monitoring the phones of passers-by, so advertisers can target messages at people whom the bins recognize.
Renew, the startup behind the scheme, installed 100 recycling bins with digital screens around London before the 2012 Olympics. Advertisers can buy space on the internet-connected bins, and the city gets 5% of the airtime to display public information. More recently, though, Renew outfitted a dozen of the bins with gadgets that track smartphones.
The idea is to bring internet tracking cookies to the real world. The bins record a unique identification number, known as a MAC address, for any nearby phones and other devices that have Wi-Fi turned on. That allows Renew to identify if the person walking by is the same one from yesterday, even her specific route down the street and how fast she is walking.