As the initial cost of investment in digital signage continues to drop and quality, capabilities and durability continue to rise, interactive digital out-of-home screens have started penetrating markets far removed from retail and corporate environments – perhaps nowhere more than in public service.

After the riots throughout England this summer, police forces went searching for ways to find the thousands of rioters and looters who had been spotted on CCTV and by other means. Struggling to locate wanted suspects, Manchester police launched a mass appeal to the general public for information about a long list of potential felons. The problem was that publishing pictures of the wanted online could only do so much good. People browse the internet at home, where felons aren't, and mobile web devices can be slow with low-resolution screens.

Police involved in Manchester's 'Shop a Looter' campaign solved that information dispersal problem by using mobile trucks called Digiadvans, from the company of the same name. Digiadvans have high-definition digital screens embedded in their sides and, in Manchester, were used to display rotating pictures of wanted looters and information about how to report suspects to the authorities. Within a few hours, according to Digiadvans, two riot suspects were apprehended. Within 24 hours a third was put into custody and a digital signage solution to one of law enforcement's oldest problems was born.

Digiadvans have also been used by police in Humberside, UK and elsewhere to help promote more general efforts to create safer communities. Crime statistics, instructions on how to report crime and general information on community safety are being displayed wherever police and local officials think those messages with have the greatest impact. Better still, where they set up the digital signage can change from day to day.

The advantages of Digiadvans and similar movable digital signage technologies for information dispersal, in particular, are two-fold. Firstly, the uniqueness of seeing a van parked in public with flashy graphical displays embedded is fundamentally unexpected and eye-catching. It leaves an impression and strengthens the impact of the message. Secondly, the mobile element gives the flexibility to place the media content of signage in a context that can strengthen its message. So if foot traffic is strongest through a town centre during the week, but police still want to reach residents at the town fair in the park over the weekend, they have the flexibility to service both those needs with no added investment.

In 2010, the Department of Homeland Security in the USA launched a digital signage campaign in 588 Walmart supermarket locations. Part of secretary of homeland security Janet Napolitano's 'If You See Something, Say Something' campaign, public service announcements featuring Napolitano reciting a brief statement were displayed on screens to 'raise public awareness of indicators of terrorism and violent crime, and to emphasise the importance of reporting suspicious activity to the proper state and local law enforcement authorities'.

Some police forces are using digital signage as an internal informational tool as well. Applications like displaying pictures and names of suspects on screens in police station canteens and other areas not accessible to the public are aimed at helping officers remember information, as they are exposed to it multiple times a day. Similar applications are also being implemented in business.

There are numerous applications for digital out-of-home installations in security. Facial recognition systems integration into existing digital signage solutions have been much anticipated from an advertising and marketing perspective. The personalisation value that biometric digital signage will bring the digital out-of-home industry will be a game-changer once it's able to scale. But along with generating commercial value, every digital signage installation with facial recognition capabilities will also be able to serve surveillance and crime detection functions.

More presently, the ability to easily overwrite scheduled content in the event of emergencies combined with the potential speed with which digital signage can disperse information is already proving invaluable. Some buildings, for instance, already equipped with digital signage, are posting evacuation instructions and emergency information in the event of a fire or fire alarm. Better still, digital signage in buildings can be automatically programmed to display evacuation information when smoke alarms go off.

Whatever the field, the flexibility of digital signage for out-of-home communication and information purposes is making it more and more appealing to more and more sectors.