Counter Strike CS GO Skins
Some of the knife skins that can be unlocked in Counter Strike: GOValve

Valve has announced that it is to do all it can to bring down unofficial gambling sites founded on its markets for in-game items, such as weapon skins in Counter Strike: GO. The news follows revelations that prominent YouTubers were heavily promoting a site called CS:GO Lotto without disclosing that they owned the site.

In a statement Valve's Erik Johnson said: "We are going to start sending notices to these sites requesting they cease operations through Steam, and further pursue the matter as necessary. Users should probably consider this information as they manage their in-game item inventory and trade activity."

Players are able to purchase keys through official means to access crates that drop random items in a number of Valve games – including Counter Strike: GO. The rarity and desirability of these items is determined on the official marketplace of Valve's digital sales platform Steam, through which players can buy items with real-money and sell them for Steam store credit.

The unofficial gambling sites in question allow users to log in with their Steam accounts through an OpenID API that the sites are (were) able to access. Once logged in, players can gamble using in-game items they've acquired, which can be worth hundreds and thousands of dollars.

Part of the process also includes these sites creating automated Steam accounts. Doing this, and accessing the OpenID API is "not allowed by our API nor our user agreements," said Johnson.

In early July You Tuber streamers Trevor 'TmarTn' Martin and Thomas 'ProSyndicate' Cassell were discovered to be the president and vice-president respectively of CS:GO Lotto – a site they had used and won a lot of money using in videos that effectively promoted the site. This was done without disclosing their relationships to the site and led to accusations of false advertising and that they rigged videos in their favour due to their access to the site's back-end.

Other YouTubers and Twitch streamers then revealed their involvement in promoting sites like it. Josh 'JoshOG' Beaver admitted to owning equity in CS:GO Lotto, while Lewis 'PsiSyndicate' Stewart revealed that videos in which he promoted SteamLotto were rigged.

Since Valve's statement, Twitch has issued their own, reiterating its rules. "Broadcasters are not permitted to stream content that breaks the terms of service or user agreements of third-parties," it read. "As such, content in which the broadcaster uses or promotes services that violate Valve's stated restrictions is prohibited on Twitch."

Valve's announcement will also play a part in an ongoing lawsuit against the gaming giant for enabling the gambling market, which isn't subject to the same rules and regulations as more traditional betting sites. CS:GO Lotto for example, once only requested that its users be over 13 − the legal gambling age in the UK is 18 − but has since changed this.

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