ETNO shared with the Article 29 Working Party the a legal memo noting that while the Guidelines provide many useful additions and clarifications, they also contain some suggestions that are particularly problematic for the industry, users and third parties.
PDF available here.
On 13 December 2016, the Article 29 Working Party published a set of Guidelines interpreting the notion of the right to data portability, as introduced by Article 20 of the General Data Protection Regulation (GDPR). While the Guidelines provide many useful additions and clarifications, they also contain some suggestions that are particularly problematic for the European telecommunications industry:
PDF available here.