Profling is not about data but about knowledge. It provides a crucial technology for a society that is flooded with noise and information. Profiling is another term for sophisticated pattern recognition, and the enabling technolgy for Ambient Intelligence. It confronts us with a new type of inductive knowledge, inferred by means of automated algorithms. To the extent that decisions that impact our lives are based on this knowledge, we need to develop the means to make it accessible for individual citizens and provide them with the legal and technological tools to anticipate and contest these knowledge claims or to challenge their implications.