This article discusses the issue of the significance of property rights in the Polish legal order in the context of the digitization of the main state registers and possible consequences of attacks on them. Technological progress makes it possible to transfer registers from a traditional paper form to a digital form. This process has also been performed in the area of Land and Mortgage Registers. Due to the above, every Internet user, who knows the number of the Land and Mortgage Register, is able to verify its legal status. There are real material values related to the data in the Electronic Land and Mortgage Registers. The above may cause that, like banking systems, also the system of the Electronic Land and Mortgage Registers, may become subject to attacks by cybercriminals. This article considers the possible effects of such actions and possibilities of protecting against them.