Article 29 The Group (A29WP), Notice 1/2010 on the concepts of „controller“ and „processor,“ February 2010, p. 21. However, a mutual benefit to treatment alone is not sufficient to establish joint control. When a company processes data but does not pursue its own processing objectives, it is simply a subcontractor and not a common manager. Similarly, the use of a common infrastructure or common data processing system will not automatically lead to a common control, particularly when processing is conducted separately and where the parties` activities do not necessarily overlap.  The protection of the rights and freedoms of the persons concerned, as well as the responsibility and responsibility of those responsible for processing and subcontractors, including the supervision and actions taken by the supervisory authorities, require a clear division of responsibilities under this regulation, even if a processing officer determines the purposes and means of treatment with other persons responsible for the treatment or when a processing operation is carried out on behalf of a person in charge of the treatment. 3. Notwithstanding the provisions of the agreement under paragraph 1, the person concerned may exercise the rights conferred on him by this regulation for and against each of those responsible for the treatment. 2. The regime covered in paragraph 1 duly reflects the respective roles and relationships of the common persons responsible for the treatment of the persons concerned. The content of the agreement is made available to the person concerned. The common control provision is a step towards greater transparency on the complex ecosystem of personal data processing.
Although a new provision, section 26 is an essential means of strengthening the person concerned by requiring transparency and accountability from those responsible for processing, particularly in cases where multiple people in charge of processing conduct complex processing operations. section 27. representatives of the processing managers or subcontractors who are not established in UNION 1. When two or more treatment managers jointly determine the purposes and means of treatment, they are jointly responsible for the treatment. They transparently define their respective responsibilities for the performance of the obligations arising from this Regulation, in particular with regard to the exercise of the rights of the person concerned and their respective obligations, to disclose the information covered by Articles 13 and 14 by agreement with each other, unless the respective responsibilities are determined by EU law or the Member States responsible for processing. The agreement may designate a point of contact for those affected. With regard to the person who may be a common responsible person, the Article 29 working group has established that even users of social networks can themselves become common for the processing of personal data when their purposes of processing personal data are no longer intended for „purely personal or private activities“.