Chat rooms have been around since the early internet. It is a common area hosted on a server where different users login and "chat" by means of typing messages.
Instant messaging (IM) has become a fun and simple way to communicate through the internet. It is interactive, real time, and you can message while performing other tasks. There are virtually hundreds (if not thousands) of IM platforms, but by far the most popular one is Windows Live Messenger (MSN Messenger) followed by
a ICQ a Yahoo! Messenger a Google messenger a Meebo (a trans-IM platform) a AOL messenger a IBM Lotus Sametime (used for internal company messaging) a Facebook Messaging
Although chat rooms and IM are very popular, and the majority of people use them for socializing and keeping in touch with friends, they still remain the breading ground of fraudsters and sexual predators.
Chat rooms and IM applications, create a trace of evidence regarding their usage. There are usually logs where the actual "chats" can be read and analyzed. The logs also provide information about the people who chat with you, and their origin.
Furthermore, if you suspect that a crime is in process or your child is in danger, there are ways of monitoring the chatting activities and collect real-time data during the actual chat. Special software is used for this covert operation. The "sniffing" of data packets allows forensic experts to see who talks to a specific computer, where is the origin of that source and what has actually been sent during the contact.