The development of 5G networks is one of the largest projects in the human civilization history. Moreover, this project was originally planned as international and covering the entire globe. During the implementation of most large projects modern science has developed a number of approaches. One of them is the project assessment based on the balance between costs, benefits and risks. The costs of many trillions of dollars for the "Development of 5G networks" project are already obvious. Dozens and even hundreds of articles in scientific journals and tabloid magazines and newspapers are devoted to the benefits of the project. The authors of the article describe the advantages and disadvantages of the 5G networks development. They offer their own classification of benefits for the 5G networks development and divide them into explicit, implicit and hidden. Moreover, the hidden advantages are apparently decisive. Special attention is paid to the potential capabilities of 5G networks to provide police functions, in particular, to ensure all issues of total surveillance of any person. The problem of risks associated with the project is covered very little. Although during the last years there appeared a number of articles that force us to consider carefully the problem of 5G networks risks, but the research on these risks is extremely insufficient. The latest scientific articles and reports made from 2020 to 2021, which deal with the adverse consequences of the 5G networks development, are analyzed in the article. A risk-cost-benefit analysis is carried out that allows concluding whether the 5G networks development is justified or not. The performed analysis raises doubts on the justification of spending trillions of rubles for the 5G networks development in the Russian Federation.