Part I: Cyberspace -- On how the Cyberspace arose to fulfill theoretical physicists' needs and eventually changed the world: Personal recallings and a practitioner's perspective -- Narrative mapping of cyberspace. Context and consequences -- A Conceptual and Legal Approach to The Cyberspace: The dilemma security vs. Freedom -- The digital revolution in underdeveloped countries: brief analysis of the Dominican Republic -- Business strategy in the digital era. Digital transformation, disruption and cybersecurity -- Impact of cyberspace on individual and group security – a human developmental psychology approach -- Part II: Cybersecurity -- Cyberspace: A platform for organized crime -- Some Criminal Aspects of Cybersecurity -- The situation and evolution of the managed services of Cybersecurity, towards 3.0 and beyond… -- Collaboration of private investigation with public institutions within the Spanish cybersecurity strategy. How private investigation gathers proof on cyber delinquency -- Psychosociological characteristics of cybercrime -- Use of cyberspace for terrorist purposes -- Mythology of Cyber-crime – Insecurity & Governance in Cyberspace: some critical perspectives -- Part III: Cyberwarfare. The Tallinn Manual and Jus ad Bellum: Some critical notes -- War-like activities in the cyberspace: Applicability of the Law of Armed Conflicts -- A Negotiation on Cyber warfare -- Security of Cyber-space in Nuclear Facilities -- Can cyber warfare prevent wars? -- Epilogue -- L. A. García-Segura.