Technology is a “pharmakon”, a Greek term that means both the poison and the remedy. This is the paradox of every technology: it brings benefits, but also has a dark side that can give rise to concerns (the negative effects, loss of control, accidents, etc.). The dark side of big data technologies lies in our fear of being “unmasked” or “revealed”, and that our behaviour will become “legible”, “interpretable” and “accessible” to all. In other words, the loss of intimacy and/or privacy. The blockchain could be the ultimate technological solution to overcome these fears and to irrevocably protect our privacy and anonymity.