This issue is addressed by the binding Position No. 1/2013, prepared by the Office for Personal Data Protection on the basis of suggestions by the CAA. This position is freely available at:

The issue of privacy and personal data protection with regard to the operation of unmanned aircraft is the subject of extensive debates just as in other countries. They have been sparked by the technological advancement, which brings along a massive growth of the possibilities to acquire video and audio recordings using unmanned aerial vehicles. Other specific features are the small dimensions and low noise footprint of most unmanned aircraft (for both commercial professional machines and recreational or sports aircraft models), allowing nearly or completely unobserved operations and recording of data for the subject of interest.