Massive leaks of official secrets, personal data leaks, electronic traceability of our movements or, also, intimacies posted on the Internet, demand for visibility and defence of privacy: secrecy and transparency are being redefined. This is what the articles by Alberto Abruzzese, Denis Bertrand, Joshua Meyrowitz, Umberto Eco, Jacques Fontanille, Paolo Fabbri or Magalí Arriola collected in this book deal with.