Max Schrems, 27, an Austrian privacy activist who is taking a class action suit against Facebook speaks at the 7th National Data Protection Conference in Dublin Castle. Picture credit; Damien Eagers 28/1/2015

A deal facilitating the transfer of data between the United States and the EU is invalid, an adviser to the European Union's top court said on Wednesday, and individual data protection authorities can suspend data transfers to third countries.

"The Commission decision is invalid," said Advocate General Yves Bot, referring to the Safe Harbor framework enabling data transfers to the United States.

Austrian law student Max Schrems had challenged it after revelations of mass US surveillance program.

The case is the culmination of an action brought against Facebook in the Irish High Court by him.

Mr Schrems argued that Facebook flouts privacy considerations in its pursuit of expansion and commercial success.

He also said that personal data processed by Facebook is unprotected because it is transferred to the US, where it is not treated properly.

Facebook, like many US firms, has chosen Ireland as a data regulation home in Europe.

Reuters