1. A computer-implemented method comprising: initiating, by at least one computer device, a neutral value as a first category-specific reputation score associated with a content topic reputation category for a first account in a social networking system, wherein the content topic reputation category corresponds to a content topic for one or more user activities in the social networking system; monitoring, by the at least one computer device, the social networking system to identify a new user activity propagating through the social networking system, wherein the new user activity is performed by or associated with the first account, wherein said monitoring includes identifying the new user activity as being associated with the content topic; adjusting, in real-time in response to identifying the new user activity as being associated with the content topic via the at least one computing device, the first category-specific reputation score for the first account in the content topic reputation category, wherein said adjusting is by increasing or decreasing the first category-specific reputation score by an amount based solely on data related to the new user activity; and publicizing the first category-specific reputation score in the social networking system to identify the first account as associated with trustworthy content in the content topic reputation category.