A US citizen is taking Cambridge Analytica to court to get access to data he says it holds on him.
Prof David Carroll filed his legal challenge on the same day Facebook announced it had banned the company from its network.
He also wants Cambridge Analytica to disclose how it came up with the psychographic profile it had on him.
Legal experts believe the case could set a precedent for how such companies collect data.
Prof Carroll, who is an associate professor at Parsons School of Design in New York, requested a breakdown of the data Cambridge Analytica held on him when it emerged the company had built profiles on up to 240 million Americans.