LinkedIn, the white-collar social network with over 500 million users has responded to an investigation that revealed the company violated data protection rules by using the email addresses of 18 million people to buy targeted ads on Facebook.

Following a complaint from a non-LinkedIn user, the Data Protection Commissioner (DPC) of Ireland conducted an audit into LinkedIn’s processing of personal data.

The DPC’s report, which doesn’t say how it acquired the 18 million email addresses, covered the first five months of 2018 (Jan-May) and concluded that LinkedIn Ireland, the data controller, used a hashed form of user email addresses to target Facebook users with ads. These ads were aimed at trying to increase sign up to its service “with the absence of instruction from the data controller as is required” to stay GDPR compliant.

“The complaint was ultimately amicably resolved,” said the DPC, “with LinkedIn implementing a number of immediate actions to cease the processing of user data for the purposes that gave rise to the complaint.”

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LinkedIn has also been instructed to delete all personal data processed during the time of unlawful processing “with the absence of instruction from the data controller”.

LinkedIn, along with other countries, has now moved its data processing from Ireland to the USA in an effort to loosen the stranglehold GDPR places around it. It avoids processing user data under law that should not apply to them. LinkedIn will have international users who aren’t EU citizens but, prior to the move, would have their data processed in a European country.

The report also details particulars about the ongoing investigation it has into Facebook and how it handles facial recognition data. Facial recognition data has special requirements under GDPR because it records biometric data. Details of Yahoo‘s data breach and the interaction between Facebook and WhatsApp are included too.