Code deployed by the ESEA League, an eSports organization with branches in North America, South America and Europe, employed ESEA Client users' computers to "mine" for the open-source digital currency bitcoins without permission, according to a pair of forum posts from co-owner Eric "lpkane" Thunberg who apologized for the action.

Thunberg initially wrote that the bitcoin mining idea, which used a distributed network of PCs to solve math problems for which they were rewarded bitcoins, began as an April Fools prank. Thunberg and company "elected to put some test code in the client and try it on a few admin accounts" before deciding "it wasn't worth the potential drama."

Although he believed the ESEA "pulled the plug" on the code, that wasn't the case.

"Fast forward to 48 hours ago, a fuck up in the client server results in a restart which results in a setting getting changed which enables it for all idle users, and here we are," Thunberg wrote.

According to a screenshot posted in the initial thread, the code netted 1.913 bitcoin "rewards," about $246, according to Simple bitcoin Converter.

In a post a few hours later, he wrote that the bitcoin miner had been running for two weeks, beginning April 14, and had earned 29.276 bitcoins, a value of approximately $3,750.

Thunberg wrote that "as the person who is ultimately responsible for everything it's 100% my fault," and wrote that a client update removed the code. The ESEA League is offering premium users a free month of service and wrote that the bitcoins earned would be added to the ESEA League's prize pot "so at the very least your melted [GPUs] contributed to a good cause."

A post on Reddit Games by Redditor "renalucario" points out that ESEA members had complained of GPU usage spikes and virus alerts caused by the mining code before Thunberg's post this morning.