Ain't as simple as "just disable them". G2A acquires keys through buy-one-get-two deals, using stolen credit cards, money laundering, stolen keys (mass mailing the devs for "preview" keys, which they then flip on G2A) etc.

So there's no way to know the origin of keys in G2A. By the time you know it's stolen keys, they've been sold out, and G2A has a notorious history of not giving a fuck about the situation.

You could just arbitrarily disable all keys, but you'd affect >90% legitimate customers.

They don't know the keys on G2A and the like unless they buy them themselves. And these unauthorized key sellers aren't in the business to cooperate with them, since the money laundering is their bread and butter.

Yeah... I hadn't heard of G2A before now, but after reading up a bit, it seems like a bit of a convenient scapegoat for developers.

https://www.gamesindustry.biz/g2a-and-wube-software-settle-usd40-000-chargeback-dispute

Some quotes

The debate over the site was triggered by No More Robots founder Mike Rose, who claimed it was better for gamers to pirate titles than buy from G2A since "devs don't see a penny either way."

Vlambeer co-founder Rami Ismail agreed, adding: "These sites cost us so much potential dev time in customer service, investigating fake key requests, figuring out credit card chargebacks, and more."

As the discourse escalated into a petition to stop G2A from allowing the sale of indie games, the marketplace responded with its 10x chargeback offer in an attempt to address these concerns.

Lack of response has frequently been an issue for G2A. To date, Factorio remains the only studio to challenge the firm's offer of 10x chargebacks, and when G2A suggested a potential keyblocker tool for developers, only 19 companies registered interest.

Klonan acknowledges Wube's role in how G2A sellers were able to obtain codes for Factorio. These codes were purchased through the game's official website, which was previously less secure than the likes of Steam or Itch.io, although did give Wube detailed records of purchases and chargebacks it could compare with G2A's audit.

The company also offers a free Steam key with website purchases, many of which are "probably flipped on G2A", although as these are obtained legally it becomes harder to challenge these transactions.

Klonan notes that after Wube switched to using Humble's widget on its site and refraining from "giving out tons of keys for giveaways to dodgy, often fake, influencers," the fraudulent purchases "stopped completely."

"In the end, contacting G2A is treating a symptom of people stealing keys," he says. "The best way to combat that is to cut it at the source.

If it were that easy then G2A wouldn’t exist. Use some common sense.

No that’s not the issue. That’s not why they’re saying pirate the game. The issue is they’re also getting hit by chargeback fees from those fraudulent sales.

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