Jim Whightman, a British computer programmer, has created ChatNannies which is designed to detect pedophiles who roam internet chatrooms looking for victims.
The software sends automated Nanniebots to chatrooms and the bots engage in conversation which is typical for children. The program then analyzes the behavior of people who chat with the bots.
If anything is suspicious in the conversation, Wrightman receives an e-mail of what was said and he decides whether or not to notify authorities. Wrightman says there are 100,000 of these bots monitoring chat rooms. Source