The generalization of smartphones has brought a wide range of mobile applications available to users. Mobile applications handle nowadays many everyday tasks from banking to communication. As the amount of data processed by mobile applications has risen, privacy has become a major concern for users. The purpose of this thesis was to examine the privacy threats to the user caused by the features and practices of mobile applications. In addition, the aim was to find out the users’ attitudes towards potential privacy threats. The thesis carried out as a literature review; therefore, its results are based entirely on previously published studies. For example, inadequate supervisory practices in application stores, excessive trust in user control, and poor application stores in appraisal of app reliability were considered threats by reviewing past studies. Users’ attitudes towards privacy were investigated by analyzing surveys. Users’ biggest concerns were the loss of information and the physical damage to the mobile device. In addition, good IT skills were found to predict a more critical attitude towards mobile applications.