EN
In certain cases of the use of the Internet, the need to limit the quantity of data loadable and/or the content to be seen by individual users is justifiable. The study deals with the technical, legal and ethical issues of such limitation in the general context of the right to unhindered access to the World Wide Web, and in two special environments: public libraries and schools. These institutions provide public access and may define some rules of 'proper use', if economic or ethical reasons make it necessary. Various practices of limiting the quantity of downloaded data, as well as methods of content filtering (for users under age) are presented, with the reservation, however, that despite all these attempts, the issue remains extremely problematic. The author presents a 'home-made' solution that is being developed at the Technical College of Budapest. The method is based on subsequent control of access log file data, but as the users in the computer rooms cannot be identified and named, no personal data are involved in the process.