MMORPG stands for Massively Multiplayer Online Role Playing Game. Which is why everyone uses the acronym because who would want to have to say that mouthful.
There are millions of people playing on-line games from the "Sims Online" to World of Warcraft and dozens of others.
The majority, if not all, of these games have a logging feature that can be turned on by the user. In-game logging is saved to the hard drive of the computer and records every message to and from the player, both in public chats and in private tells.
The logs also record all of the dates and times that the user is on-line.
Also, if you know how to get the information, most games record some information about play sessions, even if logging is not turned on.
How can any of this be of use in a case?
You can establish when a person was at their computer playing the game, to perhaps bolster or discount an alibi.
If you suspect that one partner is having an on-line affair, the logs could be a good source of private chat information.
Do you need to know how much time someone was spending on-line playing a game instead of caring for a child or working? Game logs could be a good source of information there as well.
In the connected world we live in today, pieces of information are available in so many places if you just know where and how to look for them.