hypnosec writes "The E-Sports Entertainment Association (ESEA) gaming league has admitted to embedding Bitcoin mining code inside the league's client software. It began as an April Fools' Day joke idea, but the code ended up mining as many as 29 Bitcoins, worth over $3,700, for ESEA in a span of two weeks. According to Eric Thunberg, one of the league's administrators, the mining code was included as early as April. Tests were run for a few days, after which they 'decided it wasn't worth the potential drama, and pulled the plug, or so we thought.' The code was discovered by users after they noticed that their GPUs were working away with unusually high loads over the past two weeks. After users started posting on the ESEA forums about discovery of the Bitcoin mining code, Thunberg acknowledged the existence of a problem – a mistake caused a server restart to enable it for all idle users." ESEA posted an apology and offered a free month of their Premium service to all players affected by the mining. They've also provided data dumps of the Bitcoin addresses involved and donated double the USD monetary value of the mined coins to the American Cancer Society.