This is alarmingly similar to the ESEA situation where ESEA (a premium membership gaming community) discreetly built a bitcoin miner into their anti-cheat client [1], fried some users' graphics cards and were found out then fined $1MM. [2]

[1] http://www.theverge.com/2013/5/2/4292672/esea-gaming-network... [2] http://www.wired.com/wiredenterprise/2013/11/e-sports/