Before installing Robotcop please read the following important note.

Robotcop uses client IP addresses to block requests from spiders. In some cases, this may lead to Robotcop blocking requests from legitimate users if they have the bad fortune of sharing a public IP address with an e-mail address harvester. For example, all users connecting from a NAT protected network will share the same IP address.

For this reason, very busy sites should consider setting the RobotcopExpire to a short interval, such as 10 minutes, so that IP addresses do not remain blocked for too long. As long as the spider remains active, the address will continue to be blocked, so you may also want to use the "ban" Robotcop mode to simply chase them off rather than trap them.