EVE Online is no different. The RMT (Real Money Trading) industry is massive and EVE's developers CCP have waged a constant war against it in recent years. The PLEX initiative gave players a way to safely buy ISK for cash while at the same time helping players who couldn't afford their subscriptions pay with ISK. The result was a dramatic hit to the RMT market, who had to drop their prices to compete with a legitimate service replacing their own.
As part of Operation Unholy Rage in August of last year, EVE GMs also banned over 6200 accounts belonging to farmers known to be supplying the RMT industry. The effect on the market was instant, with the population in farmed mission systems like Ingunn disappearing overnight. Almost immediately, the farmers reacted with a spate of account hackings to claw back some ISK.