Valve has removed the ability to sell and trade container keys in Counter-Strike: Global Offensive after the realization that most all key purchases were being used to facilitate fraud.

“Unfortunately this change will impact some legitimate users, but combating fraud is something we continue to prioritize across Steam and our products,” explains a blog post from Valve.

Those container keys are typically purchased to unlock Counter-Strike: Global Offensive’s loot box equivalent ‘containers’ and, like other in-game loot, can be traded or outright sold on Steam’s built-in digital goods marketplace.

However, the fraud itself wasn’t taking place between Counter-Strike: Global Offensive players. Rather, external fraudsters were using the game to redistribute their ill-gotten gains from fraudulent activity committed outside of CS:GO by buying and reselling keys on the marketplace.

“In the past, most key trades we observed were between legitimate customers,” explains Valve’s post. “However, worldwide fraud networks have recently shifted to using CS:GO keys to liquidate their gains. At this point, nearly all key purchases that end up being traded or sold on the marketplace are believed to be fraud-sourced.”