In this paper, positive and negative examples of media activity are given. The media have become a large part of society and influence it every day. In order to reduce negative influences and avoid media manipulation as much as possible, it is necessary to have knowledge of media literacy, which can be used to look critically at all information available in the media and distinguish truth from lies. The use and exposure to the media has its positive and negative sides, and both have the greatest impact on children and young people whose most used medium is the Internet. By careful and moderate use of the Internet, all its advantages can be obtained, but since everything is available to everyone, anytime and anywhere, it is difficult to avoid its disadvantages as well. Internet violence and stereotypes are the main source of negative influences, they appear every day and are difficult to avoid and remove. In addition to negative influences, media also have a large number of positive influences and can lead to various positive changes in society. The aim of this paper is to explain what the media are in general, what positive and negative effects they have on society, on the people who follow them, various stereotypes associated with the media and how they can stimulate change.