1. A system for detecting an abusive activity over a network, comprising: a computer robot (bot) that is configured to perform actions, including: proactively sending a first message in a chat room; receiving a response to the first message; and if the response indicates an abusive activity in the chat room, determining a source of the response, and transmitting the response and the determined source of the response over the network; and a network device that is configured to perform actions, including: receiving the response and the determined source of the response; dynamically revising a filter to block another message based on the response or the determined source; and dynamically retraining the robot based, in part, on the response, the determined source, and information from the blocking filter.