ESports developer Valve Corporation continues to purge online gambling sites taking advantage of its open application program interface.

Valve – the folks behind the popular Counter Strike: Global Offensive (CS:GO) eSports title – this time targeted online gambling sites catering to the first-person shooter multiplayer video Team Fortress 2 by blocking their accounts.

It isn’t clear as to how many accounts of Team Fortress 2 gambling sites have been shut but Valve said that the move is a reiteration of their position that the company doesn’t tolerate skin betting.

“In July of last year we outlined our position on gambling web sites, specifically noting that Valve has no business relationship with these sites. At that time we also began blocking many CSGO gambling accounts,” the company said in a statement posted on the TF2 blog. “More recently, some gambling web sites started leveraging TF2 items. Today we began the process of blocking TF2 gambling accounts as well. We recommend you don’t trade with these sites.”