The research used psychographic profiles for individual voters, generated using information on their publicly stated interests. 

The study sorted voters into two groups – high and low authoritarian tendencies (intended to reflect conservative and liberal social outlooks) – using age, gender, location and interest targeting. 

The two groups were then shown one of four ads that had been specially created: two for increasing support for internet surveillance, and two for decreasing it. The effectiveness of the ads was tested by measuring agreement with the statement ‘with regards to internet privacy: if you've done nothing wrong, you have nothing to fear.'

In each case, targeted ads shifted opinion much more effectively.

Quoted in a story in the Guardian, Chris Sumner, research director and co-founder of the Online Privacy Foundation, a not-for-profit organisation, said: “Before the referendum results, the concern we had was that people’s biases were being manipulated, either intentionally or unintentionally.

“Now we’ve seen this [research], I’m as concerned as I was before.

“It’s not a surprise, it’s what we expected to see. People on one side, whichever side happens to be winning at the time, are going to say ‘no, it’s not a problem’, while people who have just lost are going to see it as a big problem.”