Micro-blogging has noticeably revolutionized the way information is consumed. It has empowered citizens themselves to act as sensors or sources of information that could lead to consequences and influence, or even cause, media coverage. People share what they observe in their surroundings, information about events, and their opinions about topics from a wide range of fields. Moreover, these services store various metadata from these posts, such as location and time. Aggregated analysis of this data includes different dimensions like space, time, theme, sentiment, network structure etc., and gives researchers an opportunity to understand social perceptions of people in the context of certain events of interest. Micro-blogging also promotes authorship. On the micro-blogging platform Tumblr, the reblogging feature links the post back to the original creator.