Smart bin in London
A smart dustbin, made by Renew, in the City of London (

Special hi-tech dustbins that access the information of passers-by and sell it on to brands for targeted advertising are being trialled in London.

The technology is still in its early days, and the legality of the scheme is still uncertain.

Renew, the company that builds and sells the pod-like recycling bins, first installed them during the build-up to the 2012 Olympics . It currently has 200 units around the City of London, kitted out with wi-fi and LCD screens. The bins also offer live updates to displayed content.

Advertisers buy time on the screens, with local councils and charities receiving around 30% of screen time.

Renew has a 21-year contract to run the bins and each unit costs £30,000 to build and install.

The potentially lucrative scheme is driven by seizing a niche market - broadcasting directly to affluent professionals.

The technology in the bins can identify the phone's manufacturer and MAC address. Over the course of a week Renew reports "4,009,676 devices captured with over 530,000 uniques acquired".

The potential for new advertising methods is being scrutinised by many companies in a fiercely competitive market. For example, a coffee company can track an individual's iPhone and know they usually stop around 8am for a coffee and a croissant.

But if the individual changes habits and stops in at a rival company, then the first company could pay to flash an advert on a relevant bin just as the individual is approaching, with a reminder of a loyalty scheme or special offer.

The scheme has raised concern over personal privacy, and Renew has even faced accusations that it is breaking UK law. The company denies this. "The gist of it is that we are collecting anonymised, aggregated MAC details. We're not really collecting a personal piece of data: we don't know who anyone is," Renew CEO Kaveh Memari told The Independent.