The distribution of the vast majority of web browsers is actively encouraged by their free use. This is a common practice of web browser developers, as it provides them with great opportunities for their distribution. The flip side of this process is the collection of personal data by web browser developers that the user does not control. The collected data is automatically transferred to leading IT companies such as Google, Microsoft, and Cloudflare, which collect, accumulate, process, and monetize the users’ data in an automated manner. This leads to the fact that any web browser user is profiled in the services of leading IT companies, which receive complete information about the user's actions on the Internet. This state of affairs contradicts Article 32 of the Constitution of Ukraine, which guarantees the right to privacy and the basic provisions of the Law of Ukraine "On Personal Data Protection". The study involved long-term recording and subsequent analysis of the network traffic of Ukraine's most popular web browsers: Google Chrome, Microsoft Edge, Mozilla Firefox, and Opera. The peculiarity of the study was to obtain network traffic initiated by web browsers that have been active for a long time. To increase the reliability, the data on network connections of web browsers were obtained using two independent software tools for monitoring traffic on the network interface of a communication device. The analysis of network connections of web browsers made it possible to establish close ties between companies developing free web browsers and leading IT companies that monopolistically control the actions of users in the Internet space. This state of affairs contradicts the legal norms on ensuring the privacy of web browser users in the context of using their data without their knowledge and consent. This can be prevented using network screens operating at Layers 3, 4, and 7 of the TCP/IP stack OSI model.