Iranian players of the popular online multiplayer franchise World of Warcraft have expressed their anger at being unable to play the game due to US sanctions in place against the Islamic republic.
Game enthusiasts have gone on to the message board of the US company behind the game, Blizzard Activision, to complain about how they could not log on to the service - only to be told that US law was to blame.
"United States trade restrictions and economic sanction laws prohibit Blizzard from doing business with residents of certain nations, including Iran," the company said in an email sent to players.
"Blizzard tightened up its procedures to ensure compliance with these laws, and players connecting from the affected nations are restricted from access to Blizzard games and services."
A post to Blizzard's message board by a company employee also noted that rules meant Iranian players would not be getting refunds.
Blizzard's Warcraft franchise dates back to 1994 and has grown into a sprawling virtual world complete with its own online economy and a thriving subculture.
The games' more than nine million subscribers can log on to assume the identity of an array of fantastical characters and fight together - or each other.
It remains unclear precisely how many players are affected by the block.
Blizzard's public relations director, Rob Hilburger, said that the company does not break down player data by country or region for competitive reasons.
But he said the Iranian market compromised only "a tiny fraction" of the company's subscribers worldwide.
The US and its allies have been steadily increasing economic pressure on Iran as it tries to convince the Islamic republic to open up about its disputed nuclear programme, which Western governments fear is a cover for the development of atomic weapons.
Tehran insists the programme is intended for civilian energy generation.