A medium and method are provided for preventing undesired data from being communicated through a network. In one aspect, the method comprises the method comprises receiving from an anonymizing device an indication of an undesired data communication and an identification of one or more of a computing device responsible for said communication and a user responsible for said communication; on the basis of specified criteria, determining whether said indication is valid; when said indication is valid, incrementing a cumulative instance count that sums a number of instances associated with one or more of the computing device and the user; and, when said cumulative count exceeds a predetermined threshold number of instances, implementing a measure to prevent a further undesired data communication from said computing device.