The NSA is spying on chats in World of Warcraft and other games. There's lots of information -- and a good source document. While it's fun to joke about the NSA and elves and dwarves from World of Warcraft, this kind of surveillance makes perfect sense. If, as Dan Geer has pointed out, your assigned mission is to ensure that something never happens, the only way you can be sure that something never happens is to know everything that does happen. Which puts you in the impossible position of having to eavesdrop on every possible communications channel, including online gaming worlds.
One bit (on page 2) jumped out at me:
The NMDC engaged SNORT, an open source packet-sniffing software, which runs on all FORNSAT survey packet data, to filter out WoW packets. GCHQ provided several WoW protocol parsing scripts to process the traffic and produce Warcraft metadata from all NMDC FORNSAT survey.
NMDC is the New Mission Development Center, and FORNSAT stands for Foreign Satellite Collection. MHS, which also appears in the source document, stands for -- I think -- Menwith Hill Station, a satellite eavesdropping location in the UK.
Since the Snowden documents first started being released, I have been saying that while the US has a bigger intelligence budget than the rest of the world's countries combined, agencies like the NSA are not made of magic. They're constrained by the laws of mathematics, physics, and economics -- just like everyone else. Here's an example. The NSA is using Snort -- an open source product that anyone can download and use -- because that's a more cost-effective tool than anything they can develop in-house.