The Court of Justice of the European Union (CJEU) invalidated the Data Retention Directive (2006/24/EC) primarily because it constituted a disproportionate interference with the fundamental rights to privacy and data protection under Articles 7 and 8 of the EU Charter of Fundamental Rights. The Court found the interference to be particularly serious because the Directive mandated the retention of traffic and location data for all individuals and all means of electronic communication in a generalized and indiscriminate manner. This blanket retention applied to everyone without any differentiation, limitation, or exception based on a link to serious crime, thus failing the test of being "strictly necessary."

B. While compliance may have been financially burdensome, the Court's judgment was based on the violation of fundamental rights, not on economic considerations for businesses.
C. The Directive's invalidation was due to the nature and scope of the data retention obligation itself, not a requirement for data to be stored within the EU.
D. The Court's criticism was the opposite; it found the Directive lacked sufficient limitations, clear rules, and safeguards on how national authorities could access and use the retained data.

1. Court of Justice of the European Union, Judgment in Joined Cases C-293/12 and C-594/12, Digital Rights Ireland and Seitlinger and Others, 8 April 2014.

Paragraph 57: "It must be noted that the data retention obligation laid down by the directive covers, in a generalised manner, all persons and all means of electronic communication as well as all traffic data without any differentiation, limitation or exception being made in the light of the objective of fighting against serious crime."

Paragraph 58: "Consequently, the directive affects, in a comprehensive manner, all persons using electronic communications services..."

2. Kuner, C. (2014). The Data Retention Directive is Dead, Long Live Data Retention? International Data Privacy Law, 4(3), 169–171.

Page 170: "The Court found that the Directive violated Articles 7 and 8 of the EU Charter of Fundamental Rights... because it applied to all individuals, means of electronic communication, and traffic data without any differentiation, limitation, or exception being made in light of the objective pursued." (DOI: https://doi.org/10.1093/idpl/ipu015)

3. De Hert, P., & Papakonstantinou, V. (2014). The CJEU’s invalidation of the Data Retention Directive: a triumph for fundamental rights and a lesson in the allocation of competences. Common Market Law Review, 51(6), 1903–1930.

Section 3.1, Page 1912: The authors note the Court's emphasis on the "general character of the data retention" and that it "concerns all subscribers and registered users" without requiring any relationship between their data and a threat to public security.