1. A system for detecting an abusive activity over a network, comprising: a first 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; a second computer robot that is configured to perform actions, including: changing a status for the second computer robot to offline within the chat room without advertising an account identifier that uniquely identifies the second computer robot to the first computer robot such that a presence of the second computer robot is unacknowledged in the chat room; listening by the second computer robot for a second message; and if the second message is received by the second computer robot at the unadvertised account identifier, identifying the second message as an abusive message; 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 first computer robot based, in part, on the response, the determined source, and information from the blocking filter, and the second computer robot, such that the first computer robot learns and adapts based on shared collective information.