The book "Crimes Against Telecommunications" is a systematic study of Articles 292A-292E of the Penal Code and Articles 370-370F of the Penal Code, following Law 5090/2024, of Greek case law and the case law of the CJEU. Specific issues are examined, and certain critical practical and theoretical problems are identified, such as: | the interpretative approach to the concept, nature, and purpose of crimes against telecommunications at the European and national level | the protected legal interest, the basic crimes, aggravating circumstances, the prescribed penalties for the crimes and their compatibility with the Constitution, procedural issues, special investigative acts, etc. | the fundamental principles of "nullum crimen nulla poena sine lege certa," proportionality, etc. | the concept and characteristics of telecommunications, telecommunications data, the confidentiality of communications and specifically telecommunications, the lifting of confidentiality of communications for the investigation of crimes (Law 5002/2022), and the handling of crimes against telecommunications in the Penal Code | the relevant European case law | the legislative regulation of telecommunications in foreign legal systems | evidentiary prohibitions in the field of telecommunications in Greece | the concluding conclusions and proposals for amending the relevant legislative framework | all the basic legal aspects of Substantive and Procedural Criminal Law regarding the issues at hand, etc. The book is extremely useful for lawyers, judges, prosecutors, law students, researchers, and all kinds of legal scientists who are interested in Substantive and Procedural Criminal Law and its implications.