Big data, algorithms and predictive analytics are integral tools of modern digital media. In the process of datafication, the quantification of human lives, data is becoming the most valuable resource in the world. In this system, data representations are privileged over real beings, which defines the modern construction of reality. Ten semi-structured interviews were conducted with participants with different levels of knowledge about the subject, in order to gain insight into the practice and the lived experience of interacting with these technologies. Algorithmic selection mediates the consumption of news and information for most participants. The more passive their attitude, the more they leave the selection of relevant information to the algorithm. Since participants use a search engine to find information they need every day, the optimisation of search results can condition the visibillity of dominant narratives and information. Data mining enables the ever more precise profiling of users, based on which they are offered recommendations and advertisements. Participants describe their tactics of „negotiation” with the algorithms, in which they find their own agency. The beliefs of participants about device tapping outline the way subjective mental models mistify algorithms. Participants mostly knowingly give up their data in exchange for the comfort of certain services because they don't think the lack of privacy can seriously harm them. Such attitudes make way for different malpractices and unethical strategies, such as the use of predictive analytics in politics (for microtargeting), which is illustrated by the case of Cambridge Analytica. Human agency gains new dimensions within modern technological systems, which is why it is necessary to find a balance between personal and collective responsibility, regulation and data protection.