Even fictional currencies in virtual words are within the reach of the taxman:

Users of online worlds such as Second Life and World of Warcraft transact millions of dollars worth of virtual goods and services every day, and these virtual economies are beginning to draw the attention of real-world authorities.

“Right now we’re at the preliminary stages of looking at the issue and what kind of public policy questions virtual economies raise — taxes, barter exchanges, property and wealth,” said Dan Miller, senior economist for the Joint Economic Committee of the U.S. Congress.

“You could argue that to a certain degree the law has fallen (behind) because you can have a virtual asset and virtual capital gains, but there’s no mechanism by which you’re taxed on this stuff,” he told Reuters in a telephone interview.

The increasing size and public profile of virtual economies, the largest of which have millions of users and gross domestic products that rival those of small countries, have made them increasingly difficult for lawmakers and regulators to ignore.

...in much the same way that a weekend invitation to the Kennedy compound is hard for alcoholic philanderers to ignore.