This article discusses how the deployment of personalized systems is affected by users’ privacy concerns and by privacy legislation. It shows that these impacts are substantial and will require a significant enhancement of current systems. Basic requirements can already be met with existing technology. Most privacy laws however also impose demands that call for new technologies that still need to be researched. A central conclusion of the paper is that a uniform solution for privacy demands does not exist since both user preferences and legal stipulations are too heterogeneous. Instead, privacy will have to be dynamically tailored to each individual user’s needs, and to the jurisdiction at both the location of the personalized system and that of the user.