In case you weren't reading the site (or any gaming site) yesterday, G2A is in some hot water. The second-hand game code trading company is in dispute with game publisher TinyBuild over selling nearly half a million dollars worth of stolen game codes and keeping the profits. While the profit of G2A is far less than the retail value, the cost in chargebacks from users who's card was used to illegally purchase the games hits the publisher directly while G2A pays none of the fees.
Still confused? Just watch this video by LevelCapGaming as it clears things up nicely.