Valve have started cracking down more on sites using Team Fortress 2 [official site] items as chips in virtual gaming. Last year they focused on skin gambling with Counter-Strike: Global Offensive items, amidst scandals, more scandals, and lawsuits. Even the Washington State Gambling Commission got involved, ordering Valve to shut it all down. While Valve don't run any of these gambling sites, see, the sites do rely on Steam. Now, Valve are shutting down accounts associated with TF2 sites.
Valve said in Friday's announcement:
"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."
I've explained in more depth so many times before but here's a quick summary. So! Skin gambling sites use legitimate Steam channels and illegitimate trading bots to cash in and cash out items, in-between using them as chips for gambling from roulette to betting on professional matches. This isn't allowed by Steam. Valve are trying to kill off the accounts used by bots, which are crucial to all this. Valve's general counsel, the amazingly-named Karl Quackenbush, also sent out cease and desist letters to many sites. While that stopped some sites, even the quickest of Internet searches turns up plenty of active CS:GO skin gambling sites.
The fight continues, and apparently now includes TF2. Skin gambling with TF2 items was hardly unknown but I guess it's taken off.
Oh! Whatever happened with the WA Gambling Commission? The Man wasn't super keen on the idea of unregulated -- and potentially underage -- gambling. They had demanded Valve do what they could to stop skin gambling, seeking a response from Valve detailing their plans. Well, Valve responded (slightly late) and the most recent public declaration from the Commission, in October, said:
"Commission staff are reviewing this letter to determine if it is responsive to our request. The Gambling Commission will continue to evaluate its options regarding the violation of Washington's gambling laws."
So yes. If you gamble with virtuaguns and hats, don't be surprised if something bad happens.