Guidelines 4/2019 on Article 25 Data Protection by Design and by Default
A fundamental read for #privacy advocates in #Europe (and elsewhere).
It provides a short in depth explaination of practical aspect of the legal responsibility of data controllers under #GDPR.
For example it clarify that data protection measures (both tecnical and operational) must be designed to be EFFECTIVE and to be effective BY DEFAULT.
It also specifies that the cost of data-protection measures cannot be used to justify their lack of effectiveness, but only to peek the cheapest one among the effective ones.
And, obviously, the data controller is always accountable for such effectiveness.