Opinion of the Advocate General — ECLI:EU:C:2022:248
Date: 2022-03-31
Language of the case: Hungarian
Subject matter: Data protection
Procedure: Reference for a preliminary ruling
Origin: Hungary

Translation C-77/21 – 1 
Case C-77/21 
Request for a preliminary ruling 
Date lodged: 
8 February 2021 
Referring court: 
Fővárosi Törvényszék (Hungary) 
Date of the decision to refer: 
21 January 2021 
Applicant: 
Digi Távközlési és Szolgáltató Kft. 
Defendant: 
Nemzeti Adatvédelmi és Információszabadság Hatóság 
  
Fővárosi Törvényszék (Budapest High Court, Hungary) 
[…] 
Applicant: Digi Távközlési és Szolgáltató Kft. ([…] 
Budapest, Hungary) 
[…] 
Defendant: Nemzeti Adatvédelmi és 
Információszabadság Hatóság (National 
Authority for Data Protection and Freedom 
of Information) ([…] Budapest, Hungary) 
[…] 
Subject matter of the dispute: Administrative-law action concerning data 
protection […] 
 
Order 
This court […] refers the following questions to the Court of Justice of the 
European Union for a preliminary ruling: 
1. Must the concept of ‘purpose limitation’ as defined in Article 5(1)(b) of 
Regulation (EU) 2016/679 of the European Parliament and of the Council of 
EN 
REQUEST FOR A PRELIMINARY RULING OF 21.1.2021 – CASE C-77/21 
 
2  
27 April 2016 on the protection of natural persons with regard to the processing of 
personal data and on the free movement of such data, and repealing Directive 
95/46/EC (the ‘Regulation’), be interpreted as meaning that the fact that the 
controller stores in parallel in another database personal data which were 
otherwise collected and stored for a limited legitimate purpose is consistent with 
that concept or, conversely, is the limited legitimate purpose of collecting those 
data no longer valid so far as the parallel database is concerned? 
2. Should the answer to the first question referred be that the parallel storage of 
data is in itself incompatible with the principle of ‘purpose limitation’, is the fact 
that the controller stores in parallel in another database personal data which were 
otherwise collected and stored for a limited legitimate purpose compatible with 
the principle of ‘storage limitation’ established in Article 5(1)(e) of the 
Regulation? 
[…] [matters of domestic procedural law] 
Grounds 
Facts 
1 The applicant is one of the leading internet and television providers in Hungary. 
2 In April 2018, with a view to conducting tests and correcting errors, the applicant 
created a database known as the ‘test’ database (the ‘test database’) to which it 
copied the personal data of approximately one third of its private customers. In 
another database known as the ‘digihu’ database, linkable to the digi.hu website, it 
stored, for direct marketing purposes, the up-to-date data of newsletter [Or. 2] 
subscribers and of systems administrators that provide access to the website 
interface. This database contained the data of almost 3% of its private customers 
and the user data of forty systems administrators with full or partial administration 
rights. 
3 On 23 September 2019, the applicant became aware that the personal data (name, 
mother’s name, place and date of birth, address, identity card number or, as the 
case may be, personal number, e-mail address, landline and mobile telephone 
numbers) of a total of some 322 000 data subjects (297 000 customers and 
subscribers and 25 000 newsletter subscribers) had been accessed via the 
www.digi.hu website. It was the hacker himself who alerted the applicant to the 
attack, in writing, in an e-mail of 21 September 2019, in the process producing, by 
way of evidence, one of the records from the database and explaining the 
technicalities of the error. The applicant then corrected the error, concluded a 
confidentiality agreement with the ethical hacker and offered him a reward. The 
‘digihu’ database was not affected by the attack but it could have been. 
DIGI 
 
3 
4 On 25 September 2019, the applicant reported the personal data security breach to 
the defendant, which responded by launching an official review procedure on 
8 October 2019. 
5 By decision […] of 18 May 2020, the defendant found as follows: 
(a) that the applicant had infringed Article 5(1)(b) and (e) of the Regulation in 
having neglected, once the necessary tests and corrections of errors had been 
carried out, to delete the test database affected by the data security breach, 
which was originally created to correct errors, and in having thereby stored 
in the test database a large volume of customer data for almost a further year 
and a half for no purpose and in such a way as to allow those customers to 
be identified, and that the failure to take the measure (to delete the test 
database) had directly facilitated the personal data security breach; 
(b) that the applicant had infringed Article 32(1) and (2) of the Regulation. 
The defendant ordered the applicant to review all its databases containing personal 
data with a view to determining whether there were grounds for applying an 
encryption system to them and to inform it of the outcome of that review. It also 
imposed on the applicant a data protection fine in the amount of HUF 100 000 000 
and ordered that the decision be published. 
6 In the grounds of its decision, the defendant cited the following provisions of the 
Regulation: Article 2(1); Article 4(12); Article 5(1)(b) and (e) and (2); 
Article 17(1)(a); Article 32(1)(a) and (2); and Article 33(1), (2), (4) and (5). 
7 The defendant noted that the Regulation has been applicable in Hungary since 
25 May 2018 and that, since the data processing affected by the personal data 
security breach (storage of customer data) carried on after that date, the 
Regulation was applicable in this case pursuant to Articles 2(1) and 99(2). 
8 It stated that the purpose of creating the test database (to conduct tests and correct 
errors) was different from the initial purpose of processing the personal data 
stored in the database (to perform contracts), given that correcting the errors had 
also caused the purpose other than data processing (to conduct tests and correct 
errors) to disappear. Consequently, the failure to delete the databases after the 
errors had been corrected constituted an infringement of the fundamental principle 
of ‘storage limitation’. 
9 As regards data security measures relating to data storage, the defendant took the 
view, principally, that the data security breach could be put down to the – long-
known about and repairable – vulnerability of the ‘Drupal’ content management 
system used by the applicant, the errors in which the applicant had not corrected 
because the available repair package was not official. Relying on an expert report 
on information security which had been submitted in the course of the procedure, 
the defendant stated that the security breach could have been remedied with 
appropriate software, regular vulnerability checks and appropriate encryption, but 
REQUEST FOR A PRELIMINARY RULING OF 21.1.2021 – CASE C-77/21 
 
4  
the applicant, in not taking such measures, had infringed Article 32(1) and (2) of 
the Regulation. 
10 In addition, the defendant imposed on the applicant a data protection fine in 
accordance with Article 83(2) of the Regulation and certain provisions of the az 
információs önrendelkezési jogról és az információszabadságról szóló 2011. évi 
CXII. törvény (Law CXII of 2011 on the right to self-determination as regards 
information and freedom of information). 
Subject matter of the dispute 
11 The applicant brought an administrative-law action against the defendant’s 
decision. [Or. 3] 
12 As regards the principle of ‘purpose limitation’, the applicant claims that the 
customer data transferred to the databases in question were collected legitimately 
for the purposes of concluding subscription contracts, in accordance with 
Article 6(1)(b) of the Regulation, and that that purpose did not change when the 
test database affected by the data security breach was created. The applicant 
created the test database in order to store the data in question so as to continue to 
have them available for the legitimate purpose for which they were initially 
collected. Consequently, the creation of the test database, that is to say, the act of 
storing the data collected in another internal system, is not incompatible with the 
purpose of collecting those data. The applicant submits that the principle of 
‘purpose limitation’ does not indicate in which internal system the controller may 
process legitimately collected data, any more than it prohibits the copying of 
legitimately collected data. The applicant claims that the scope of the personal 
data processed was not extended by the creation of the test database and that, in so 
far as the creation or retention of that database may have increased the risks to the 
security of the data, this cannot be considered to be an infringement of a basic 
principle, but may, at most, be regarded as a data security issue for the purposes of 
Article 32 of the Regulation. It therefore claims that, in also keeping in the test 
database customer data stored for a legitimate purpose, it did not infringe 
Article 5(1)(b) of the Regulation. 
13 As regards the principle of ‘storage limitation’, the applicant claims that, since the 
customer data were not processed with a view to correcting errors, the data storage 
period cannot be determined by the purpose of correcting errors. Consequently, it 
did not fail to fulfil the data storage requirement by not deleting the test database 
immediately after the errors had been corrected, since it was entitled to store the 
data contained in the test database in such a way as to allow the data subjects to be 
identified, irrespective of any correction of errors. Nor, therefore, can it be 
accused of infringing Article 5(1)(e) of the Regulation. 
14 The applicant has asked the referring court to submit to the Court of Justice of the 
European Union a request for a preliminary ruling on, inter alia, the foregoing 
matters. 
DIGI 
 
5 
15 The defendant contends that the applicant’s claims should be dismissed. It submits 
that, in this instance, there is no relevant question capable of forming the subject 
of a preliminary ruling. 
Relevant EU law 
16 According to Article 5(1)(b) of the Regulation, on principles relating to the 
processing of personal data, such data are to be collected for specified, explicit 
and legitimate purposes and not further processed in a manner that is incompatible 
with those purposes; further processing for archiving purposes in the public 
interest, scientific or historical research purposes or statistical purposes is, in 
accordance with Article 89(1), not to be considered incompatible with the initial 
purposes (‘purpose limitation’). 
17 In accordance with Article 5(1)(e) of the Regulation, personal data are to be kept 
in a form which permits identification of data subjects for no longer than is 
necessary for the purposes for which the personal data are processed; personal 
data may be stored for longer periods in so far as the personal data will be 
processed solely for archiving purposes in the public interest, scientific or 
historical research purposes or statistical purposes in accordance with 
Article 89(1) subject to implementation of the appropriate technical and 
organisational measures required by this Regulation in order to safeguard the 
rights and freedoms of the data subject (‘storage limitation’). 
Relevant Hungarian law 
18 The Regulation is in force in Hungary and has been applicable since 25 May 
2018. The questions referred for a preliminary ruling relate to the application of 
the Regulation. [Or. 4] 
Reasons why the request for a preliminary ruling is necessary 
19 The matters on which the referring court seeks guidance from the Court of Justice 
of the European Union concern the interpretation to be given to the principle of 
purpose limitation established in Article 5(1)(b) of the Regulation and to the 
principle of storage limitation established in Article 5(1)(e) of the Regulation. 
20 The customer data which the applicant incorporated into the test database affected 
by the data security breach were collected for the purposes of concluding 
subscription contracts, in accordance with Article 6(1)(b) of the Regulation, and 
the lawfulness of this has not been called into question by the defendant. 
21 The referring court asks whether the copying to another database of data which, as 
is common ground between the parties, were collected for a limited purpose 
changes the purpose of collecting and processing the data. It also falls to be 
REQUEST FOR A PRELIMINARY RULING OF 21.1.2021 – CASE C-77/21 
 
6  
determined whether the fact of creating a test database (that is to say, keeping in 
another system data collected for a limited purpose) and continuing to process 
those customer data in this way is compatible with the purpose of collecting the 
data. 
22 The referring court takes the view that the principle of purpose limitation does not 
provide any clear indication as to which of the controller’s internal systems are 
ones in which the controller may process legitimately collected data, or whether 
that controller may copy such data to a test database without changing the purpose 
of collecting the data. 
23 If creating a test database (that is to say, keeping data in another internal system) 
is not compatible with the purpose of collecting the data, the referring court asks, 
in connection with the principle of storage limitation, whether, in so far as the 
purpose of processing the customer data in another database was not to correct 
errors but to conclude contracts, the necessary storage time is determined by the 
correction of errors or by the performance of contractual obligations. 
24 […] [matters of domestic procedural law] 
25 […] [matters of domestic procedural law] 
Final part 
Budapest, 21 January 2021. 
[…] [Signatures]