"How many tennis balls can fit in a passenger plane?" Neeraj, a young economics graduate from the premier Indian Institute of Technology (IIT), was given 15 minutes to solve this question during his interview rounds at Nation With Namo (NwN), one of the in-house political consultancies of India's governing Bharatiya Janata Party (BJP). He got the calculation right and joined a small team of graduates from India's top universities who were dispatched to the eastern state of Tripura to conduct surveys, collect and analyse voter data for elections that were due in February last year. Their job was to identify who was not voting for the BJP, separate them into demographic cohorts – age, gender, caste, tribe, religion – find a common concern, issue or fear and strategise how to exploit that in the BJP's favour. And they were to do all this while staying under the radar.

Cambridge Analytica, the political consultancy at the centre of the Facebook data-sharing scandal, is shutting down. The firm was accused of improperly obtaining personal information on behalf of political clients. According to Facebook, data about up to 87 million of its members was harvested by an app and then passed onto the political consultancy. The social network said its own probe into the matter would continue. "This doesn't change our commitment and determination to understand exactly what happened and make sure it doesn't happen again," said a spokesman.