Facebook has significant concerns about its ability to deliver its services to its 400 million European users over the Data Protection Commissioner's decision regarding the transfer of data to the social media giant's US parent, the High Court has heard.

Late last month the Data Protection Commissioner (DPC) informed Facebook Ireland, which is the EU HQ of Facebook and Instagram platforms, that it has made a preliminary draft decision that personal data should not be transferred to the US parent Facebook Inc.

Arising out of the decision Facebook Ireland, represented in court by Declan McGrath SC and Francis Keiran Bl, seeks to have that decision quashed.

At the High Court, Mr McGrath said that on 28 August the DPC informed Facebook it had opened an inquiry at its own volition in light of a judgment from the Court of Justice of the European Union handed down last July.

This came as a surprise to Facebook as it had not been aware of the inquiry prior to the communication.

The CJEU, in proceedings involved the DPC, Facebook and data protection activist Max Schrems, ruled that a key arrangement designed to protect EU citizens' personal data when it is transferred to the US is invalid.

The DPC said it had arrived at a draft preliminary decision that data transfers outside of the EU should be suspended as they were made in circumstances which fail to guarantee a level of protection to data subjects equivalent to those provided for in EU law.

Counsel said that this view, if adopted, would have "extremely significant adverse effects on Facebook, its business and many millions of users".

Counsel said Facebook and Instagram have over 400m users in the EU as have over 25 million businesses that use apps it provides. Its platforms also generate billions of Euro annually, counsel added.

Counsel said that the challenge aimed at quashing the decision has been brought on several grounds including that there was a failure by the DPC to conduct an inquiry before it reached its decision.

It was also concerned that the DPC had prejudged or prematurely judged the matter, and has taken irrelevant matters into account when arriving at its draft preliminary decision.

Counsel said Facebook had not been afforded fair procedures. In what is a complex matter it had been given only three weeks from the receipt of the DPC's daft finding to make submissions on the decision.

Counsel added that Facebook also believes that it is being treated unfairly. Other businesses are involved in data transfer out of the EU to other countries or organisations, yet his client was the only one subject to this type of inquiry and decision. 

The DPC, counsel said, in reaching its view has departed from procedures it had included in its 2018 report.

Counsel added that Facebook was further concerned that it is facing simultaneous investigations into the same matter at the same time.

Counsel said that it is continuing to investigate complaints made by Mr Schrems several years ago, which is ongoing.

In its action Facebook Ireland seeks orders against the DPC quashing the commissioner's preliminary draft decision in relation to the data transfer, and the decision to commence an inquiry under the 2018 Data Protection Act.

Facebook Ireland also seeks various declarations including that the DPC has acted unlawfully, has failed to carry out its functions, and has departed from its publicly declared procedures.

It further seeks a declaration that the DPC has acted disproportionately and in breach of Facebook's right to fair procedures under the Irish Constitution, GDPR, ECHR EU Charter of Fundamental Rights.

Permission to bring the challenge was granted, on an ex-parte basis, by Mr Justice Charles Meenan. The judge said he was further satisfied to put a stay on the DPC's probe, pending the outcome of the action.

The DPC, the judge added, could apply on notice to Facebook to seek to have that stay lifted.

The matter will return before the court in November.