Public shaming is back on the agenda. From fears of being photographed eating on the tube, to apps that erase pics from the night before – the spectre of public criticism looms large. Has social media revived this age-old mechanism of control? Or can shame be a force for positive change?

Shopping as we know it could be about to change. With over 50% of e-commerce traffic coming from mobile devices, an app called Tango is catering to a generation that’s stuck staring at their smartphones. With the ability to chat, share and buy all in one place, could rivals be left behind?

Will we continue to talk less and message more? Which social media platform will be a stand-out success? Will Line take over the West and how will the trend for unbundling develop?

What were the underlying themes at Cannes Lions 2015? From encouraging people to improve themselves through the power of shame to enabling people to improve the world through digital channels, many of this year's winners set out to encourage positive behaviour change.