Facebook's unprecedented Supreme Court appeal aimed at halting a referral to the European Court of Justice (CJEU) concerning the validity of EU-US data transfer channels will be heard in January.

The court previously set a provisional hearing date of December 19th but, following a case management hearing on Thursday, has now fixed the case for January 21st.

A UK-based data protection expert, Kevin Cahill, applied on Thursday to be joined to the appeal as an amicus curiae, assistant to the court.

Mr Cahill said he worked within the computer industry for 10 years before becoming a journalist writing about the industry. He also worked as an assistant to Liberal Democrat leader Paddy Ashdown, was a chair of the Human Rights Committee in the House of Lords and an adviser on surveillance and supercomputers.

The Prism programme, used by the US National Surveillance Agency to collect and store huge quantities of data of internet users, was a "big issue" in the UK parliament and was also described by the High Court here as involving "mass and indiscriminate surveillance", Mr Cahill said.

He also said "issues of fact" published by the UK parliament were "in serious conflict with the way the legal procedure is going" in Ireland.

High Court judgment

In reply to Ms Justice Elizabeth Dunne, Mr Cahill said he was aware the Supreme Court determination agreeing to hear Facebook's appeal concerned a High Court judgment by Ms Justice Caroline Costello of October 2017 and her subsequent referral of issues arising from that judgment for determination by the CJEU.

Ms Justice Dunne said the Supreme Court determination permits an appeal by Facebook on "very limited issues of law".

Mr Cahill said there was “clearly a conflict” between the facts he had and some of those before the court. “My field is facts, not law,” he said.

Giving the three-judge court’s ruling refusing his application, Ms Justice Dunne said Mr Cahill appeared to have extensive experience in areas of data protection and information technology and had given evidence on behalf of reputable bodies in that regard.

He had accepted the assistance he could provide related to factual issues when the issues before the court were very much tied up with issues of law, she said. In the circumstances, the court would not join Mr Cahill as an amicus to the appeal.

Application opposed

Lawyers for Facebook and Max Schrems, whose complaints that Facebook's sending of his personal data to the United States breached his data privacy rights led to the proceedings, opposed Mr Cahill's application, while the Data Protection Commissioner adopted a neutral position.

The Facebook appeal, expected to last up to three days, will address issues including whether there is any entitlement in the first place to appeal a reference to the CJEU.

Facebook maintains it can appeal a reference.

It also contends the High Court made incorrect findings of fact including in relation to US law on foot of which it concluded the Data Protection Commissioner had “well-founded concerns” about the adequacy of protections in the US for data privacy rights of European Union citizens.

It also argues the Supreme Court should find the Privacy Shield agreement between the EU and US means there is no requirement for a reference.

Last May, Ms Justice Costello directed a referral to the CJEU of 11 issues concerning the validity of European Commission decisions approving data transfer channels known as standard contractual clauses.

The questions raise significant issues of EU law with huge implications, including whether the High Court was correct in finding there was “mass indiscriminate processing” of data by US government agencies under the Prism and Upstream programmes authorised there.