The functional magnetic resonance imaging (fMRI) techniques are a potent probe able to visualize brain functions, by analyzing modification of blood oxygenation, and see the action in specific brain areas in response to activity or thoughts. fMRI thus promise to be a formidable tool not only to draw a new cartography of brain functional areas, but also a new tool to understand some aspects of brain function’s evolution, as well to get insights and to breach the wall into cognition, morality and consciousness. Nevertheless fMRI is not deprived of pitfalls such as limitation in spatial accuracy, reliable reproducibility of brain scan amongst different individuals or in the same person at different stages of life ( age or health versus disease), the different time scale of fMRI measurements (seconds) and neuron’s action potentials (milliseconds). Thus often caution is required in the appreciation of fMRI results and conclusions, that could lead to incorrect interpretation of brain signals and induce to draw spurious conclusions. New applications combining fMRI and real time visualization of one's own brain activity in healthy volunteers or patients promise to enable individuals to modify brain response and thus therapeutically or with other goals intervene in modifying individual behaviors. Specially this last aspect, as well as the concern about the confidentiality and storage of sensible information or forensic uses of such approaches, raises the problem of mind privacy and new ethical questions.