1. A method of detecting software robots in client computers, the method comprising: determining dynamic IP (internet protocol) addresses that have been dynamically assigned to a client computer to allow the client computer to communicate over a computer network, the client computer being a personal computer employed by a home user; receiving, at the client computer, from a server computer bot event profiles, which include web sites hosted by zombie computers infected by software robots and indicate IP addresses involved in malicious online activities perpetrated by software robots and time frames when the malicious online activities occurred; comparing the bot event profiles at the client computer with the dynamic IP addresses that have been assigned to the client computer to determine if any dynamic IP address, within said indicated time frames, that has been dynamically assigned to the client computer is involved in a malicious online activity indicated in the bot event profiles; and in response to said comparing, deeming the client computer as infected by a software robot when a result of the comparison indicates that a particular dynamic IP address has been dynamically assigned to the client computer during a time frame when a bot event indicated in the bot event profiles occurred.