The presented article is intended to determine the share of information crimes in the чstructure of Russian extremist and terrorist criminal practice and, as a consequence, to propose efficient methods of countering information crimes specifically for combating these crimes in general. The solution to this problem is implemented by applying statistical analysis of official data on criminality metrics supported by legal hermeneutics and sociological methods, combined with a historical approach to the subject. It is discovered that modifications in the legal regulation of information crimes in the Criminal Code have largely led to changes in the number of registered extremist and terrorist crimes in general. The article reveals a significant share of information crimes in the structure of extremist activity. Even after a decrease in 2019, it still accounts for about a third of all extremist crimes. In the structure of terrorist activity about every 10th terrorist crime is an information crime. In the extremist criminal activity and approximately in a half of all terrorist crime cases, illegal information is generally disseminated through the Internet. In approximately 75 % of cases, the extremist or terrorism-related information is disseminated in the Internet by people aged under 30 years old. The vast majority of all convicts are unemployed people without higher education. The system for preventing dissemination of extremist and terrorist information should be retargeted to improve the legal culture, including the value of each social group, as well as the Internet communication culture