Machin (2010), studied the issues of social networking tools in his MA thesis and categorized those on the basis of the literature review into 11 categories. The starting point for this categorization and inspiration was the article The Dark Side of Information: Overload, Anxiety and Other Paradoxes and Pathologies by Bawden and Robinson (2009), where they identify some of the “pathologies” in the information on the Web 2.0 and social networks.

Further additions to their views resulted in the present structure, subdivided in different issues:

• trust,
• decision making,
• users' satisfaction,
• information overload,
• quality control,
• loss of identity,
• permanence,
• repackaging,
• crowdsourcing,
• privacy and
• the clash with the real world.

This categorization of issues by no means pretends to include every issue or to be an extensive and final list. Most of them come from an information science perspective, some of them are also applied to studies for traditional or printed documents and some others are applied for the web, so they are not exclusive for social networks. As information systems and sources, social network applications also have these issues, the degree on which they affect and concern social networks studies may vary.