The aim of this bachelor's thesis was to describe the importance of computer literacy from a security perspective. Information systems, security of Internet and information systems will be described as well as the development of the Internet, communication and computing technologies affecting the security of users. The types and targets of attacks on information systems according to the most common forms of misuse will be described. The bachelor's thesis describes the tools and methods of information system protection, from basic physical protection to technical, program and data protection. Protection of information systems from a legal point of view will be described as well as how legal reform follows the information and communication technologies. The system's privacy and its legal protection will be defined. The necessity of legal reform regarding the presence of computer crime in the economy will be described. The impact of misuse of intellectual property and the regulations of the protection of intellectual property from the legal aspect will be described.. Activities brought by Internet development requires legal reforms, so it will be described in which areas the reform measures are being relate. The results of the questionnaire survey in the bachelor's thesis will show how much computer literacy affects the security of information systems.