By the late 1960s, the hippy movement had already identified, and warned against, the potential for machine intelligence to shape public opinion.

More than fifty years later, questions are being asked about the role social media has played in US presidential elections and the UK referendum on membership of the European Union.

By feeding people information that reinforces the beliefs they already hold, social media can exaggerate 'group think'. Manipulated in this way, people come to believe their own views are the norm and they are part of a 'correct majority'.

'Computers Control Opinion' is part of socialart.work, a mass public art project by public artist

Martin Firrell

calling for greater social justice.

It aims to create debate about power and gender, women's equality and masculinity, alternative forms of economic and social organisation, black power, and solidarity between people from different backgrounds and ethnicities.

It includes posters, publications and events supported in 2018-19 by the artist's residency with leading Out of Home media company

Clear Channel UK.