This Specialist’s Thesis aims at determining the possibility of learning about and the quantity of collected information about the habits of users of Internet Protocol television (IPTV) in Croatia on the basis of unauthorised monitoring of the IPTV traffic in the users’ home network. The Thesis does not explore the possibility and the manner of achieving the unauthorised access to the users’ home network itself; instead, it is assumed that it has already been obtained. The Specialist’s Thesis describes in detail: the IPTV technology, architecture and IPTV system components, video standards, methods of communication and IP protocols used, as well as the types of different IPTV services, with an overview of the IPTV market in Croatia and in the world. The experimental part of the thesis includes the collection of the IPTV traffic in the carrying out of ordinary user activities (initiating the STB devices, switching TV channels, use of the programme guide, programme recording, using the video library, etc.) in the IPTV service users’ home networks of two leading electronic communications operators in Croatia. Based on the collected data, the manner of communication exchange between the STB device and the monitored operator’s network is described for each of the user activities, and the analysis of the collected information is carried out from the standpoint of indicating at user behaviour and breach of users’ privacy. On the basis of the conducted analyses, the conclusion is drawn about the possibility of the breach of privacy by unauthorised persons through the monitoring of the IPTV traffic in the service users’ home network.