1. A computer-implemented method comprising: receiving a new user log on, the new user log on being associated with the new user initially signing up for an online service; monitoring, by at least one computer, new user activities, including the user's first actions after signing up for the online service, at least some new user activities comprising file-related actions associated with file sharing, at least some file-related actions comprising uploading one or more files using the online service; logging, by at least one computer, the new user activities, the logging including logging an identifier of the one or more uploaded files and a number of total file uploads; transmitting the new user activities to a reputation service; receiving, from the reputation service a reputation category of the new user, the reputation category assigned to the new user based on a comparison of the new user activities with a collection of historical activities associated with other users that indicate whether or not the new user activities are associated with a pattern that indicates an abuse pattern; and allowing or disallowing, by at least one computer, new user actions for the particular new user based upon the reputation category of the new user received from the reputation service.