The work presented in this dissertation focuses on the task of predicting the privacy class of images posted on social media. In particular, the results we are going to show aim at supporting the hypothesis that abstract concepts are better suited for capturing the private nature of content shared online. The definition of abstractness we adopted along this work refers to the idea of something that is elevated from anything concerning the sphere of perceptions, difficult to be appreciated through our senses or impossible to conceptualize as something even remotely physical. We developed a novel approach to investigate this hypothesis about abstractness in the context of a specific task.