The data firm that helped Trump win is now being probed about Brexit

A little-known data firm that claimed to have played a key role in last year's U.S. presidential election is being targeted in an inquiry about the misuse of personal data during last year's Brexit referendum.

The UK's privacy watchdog, the ICO (Information Commissioner's Office) has confirmed the opening of an inquiry into Cambridge Analytica, a tech company mainly owned by a Trump-linked hedge-fund billionaire, Robert Mercer.

“We have concerns about Cambridge Analytica’s reported use of personal data and we are in contact with the organisation," an ICO spokesperson said.

“We are also conducting a wider assessment of the data protection risks arising from the use of data analytics, including for political purposes, and will be contacting a range of organisations. We intend to publicise our findings later this year.”

Psychographic profiling

Cambridge Analytica, an offshoot of British company SCL group, uses data analysis to build "psychographic" profiles of people that could predict their voting intentions.

To do so, it harvests billions of data from social media, credit card histories, voting records, consumer data, purchase history, supermarket loyalty schemes, phone calls, field operatives, Facebook surveys and TV watching habits.

Mercer, a Trump backer and Breitbart investor, is a friend of former Ukip leader and Leave campaigner Nigel Farage.

Last week, The Observer reported that the billionaire directed Cambridge Analytica to provide "expert advice to the Leave campaign on how to target swing voters via Facebook".

According to British law, all donations of services-in-kind worth more than £7,500 ($9,166) need to be reported to the electoral commission. No donation from Cambridge Analytica or Mercer to the Leave campaign had been submitted.

A spokesman for Cambridge Analytica said the company "did not do any work (paid or unpaid) for the Leave.EU campaign."

"In 2015 the company was in discussions to potentially work with them. That work did not go ahead," he said. "We are in touch with the ICO, and are happy to demonstrate that we are completely compliant with UK and EU data law.”

Privacy concerns

Privacy experts have also expressed concerns about the firm's use of big data.

Unlike the U.S., where companies can use third-party data without seeking consent, European law allows the collection of personal data of individuals only where the individual has "unambiguously given his or her consent, after being adequately informed."

After the Trump's victory in November, Christopher Weatherhead, a technologist at Privacy International, said that despite the fact that some of the data is already in the public domain, people are probably unaware that it could be used for targeted ads. 

"It is disturbing that people who share their stories online, who use the internet to educate themselves and explore, are being secretly monitored by companies who are profiling them, and selling the profiles, or digital doppelgängers, to a political party," he said.

"Is it possible to opt-out? There must be more public discussion around these issues," Weatherhead continued. "It is troubling that such detailed pictures of peoples' lives are able to be created without their knowledge that it is even happening."