This book constitutes the thoroughly refereed joint post proceedings of two international workshops, the 6th International Workshop on Data Privacy Management, DPM 2011, and the 4th International Workshop on Autonomous and Spontaneous Security, SETOP 2011, held in Leuven, Belgium, in September 2011. The volume contains 9 full papers and 1 short paper from the DPM workshop and 9 full papers and 2 short papers from the SETOP workshop, as well as the keynote paper. The contributions from DPM cover topics from location privacy, privacy-based metering and billing, record linkage, policy-based...