Metro cops use blunt message to reach teenagers

However, research undertaken by London's Metropolitan police revealed that teenagers carry knives in the belief that the weapon will offer protection.

The Met needed to communicate that the reverse was true, that nine times out of ten the knife will not provide protection but instead end up being used on the person carrying it.

The police wanted to find a way to engage young people in some consequential thinking. 'Chose a different ending' was a YouTube film campaign that used Annotation Technology to enable viewers to choose what happened next - Carry a knife? Go to a party? Stab an opponent? After experiencing the consequences of their choices, viewers could 'Choose a Different Ending' - 21 films, 10 different endings.

Seeded online, the campaign appeared unbranded - removing any potential stigma of being a "public safety film", employing social media, search, in-game posters and blogs.

As a result, the average viewer engagement of nine films -Average rating of 4.6 out of 5 -80 YouTube comments a day -Awareness of 78% - the highest ever for a Met campaign -2 628 350 views.

Choose a different ending