The Information Commissioner's Office (ICO) has said it will be questioning Facebook about privacy issues around the social network's controversial mood experiment.
Users and analysts have been in uproar over recent news that Facebook allowed researchers to manipulate the positive and negative information that users saw on their news feeds to test their emotions. The study, conducted over a week in January 2012 and affecting about 700,000 people, was published in the Proceedings of the National Academy of Sciences.
An ICO spokesperson said: "We're aware of this issue, and will be speaking to Facebook, as well as liaising with the Irish data protection authority, to learn more about the circumstances."
The Irish interest has been prompted by Facebook having its international headquarters based in the country.
The Irish Data Protection Office confirmed that it has been in touch with Facebook "in relation to the privacy issues, including consent, of this research".
"We are awaiting a comprehensive response on issues raised," the spokesperson for the Irish Data Protection Office said.
Although the UK ICO said that it was just making a "general" enquiry at this stage, the second principle under the Data Protection Act, 'processing personal data for specified purposes', is relevant to the enquiry.
Principle two of the Act aims to ensure that organisations are open about their reasons for obtaining personal data, and that what they do with the information is in line with the reasonable expectations of the individuals concerned.
In practice, this means that companies should be clear from the outset about why they are collecting personal data and what they intend to do with it. They also have a duty to give privacy notices to individuals when collecting their data, and ensure that if they wish to use the personal data for any purpose that is different from the originally specified purpose, the new use is fair.
In a statement, Facebook's director of European public policy Richard Allan said: "It's clear that people were upset by this study and we take responsibility for it. We want to do better in the future and are improving our process based on this feedback.
"The study was done with appropriate protections for people's information and we are happy to answer any questions regulators may have."