Exotic names; assumed identities; violent preoccupations: Of course the National Security Agency was interested. And in an age of virtually unchecked government information collection, the agency wasn't about to be distracted by the fact that none of it actually existed.

Last week's revelation that American and British spies monitored online video games underscores the ubiquity and questionable utility of much of our post-9/11 surveillance, as well as the inadequacy of its official oversight.

The virtual espionage efforts, revealed in the latest leaks by NSA contractor-on-the-loose Edward Snowden, focused on online, multiplayer entertainment involving millions of Americans and foreigners: World of Warcraft, a Dungeons and Dragons-style game; Second Life, a virtual world more closely inspired by our own; and Xbox Live, a community of game console and computer users with access to a variety of diversions.

Despite a shortage of evidence that the games are havens for anything but teenagers and other socially challenged but largely harmless groups - people who pose a threat mainly to the nation's supplies of Mountain Dew and pizza - the NSA speculated that they could provide a medium for terrorist communication and plotting.

Starting around 2007, spy agencies gathered data on the games and deployed agents to infiltrate them as players. There were enough such snoops virtually bumping into each other that a "deconfliction" unit had to sort out the confusion.

Of course, spies are supposed to spy. It's up to the president and Congress to restrain them from unnecessary intrusions and protect civil liberties to the extent they can.

NSA chief Keith Alexander told lawmakers last week that another dubious espionage program, the mass collection of Americans' phone data, is indispensable. That should not be for him alone to judge.