As reported in The Guardian [theguardian.com], billboards that monitor people's responses have been installed inside apartment blocks in twenty British cities.
The billboards are supplied by 30Seconds Group who say there could be such billboards installed in the communal areas of a thousand buildings by the end of the year.
The billboards are placed in locations where people have no option but to be observed, such as areas where they wait for lifts (elevators) to arrive.
Jake Hurfurt from Big Brother Watch [bigbrotherwatch.org.uk] was quoted as saying, "We should all be able to move around the buildings we live in without being scanned against our will to monitor our personal characteristics or if we paid attention to an advert, and it is even more galling that residents of some buildings have to pay to be watched.”