G2A, Kinguin and other major reseller are absolute trash and they are allowing users to scam while taking a fee themselves.
In 2017, a lot of YouTubers and previous partners from G2A left G2A due to this...
This is better to explain with an example, so here we go.
Jimmy has just bought 100 stolen credit cards with 20,000 USD each in them for 20,000. But the problem is, the money inside the credit cards are "dirty" which means if he just transferred it into his bank account, he would be easily be caught. So Jimmy does this: Currently, there is a sale for an indie game "The crypto game". Its price is 50 dollars for a copy, and Jimmy then buys 4000 of these copies with this stolen credit cards. He then goes on a key seller site, G2A or the smaller site, kinguin and then sells it for a steal! Just 20 dollars a copy. G2A facilities of all this and they don't care what is being done on their platform. The most they do is banning the account and taking whatever remaining money is left in the account. Then eventually when the people with the stolen credit cards finally see their money gone, they put in a request and eventually get refunded. The indie devs are then forced to give back a lot of profits
and are hit with a couple dollars chargeback fee, so they don't just lose a bunch of sales, they also lose money.
Due to G2A's carelessness and obliviousness, they are allowing these thieves to abuse their platform and they are also taking a cut of their dark money [1] and laundering the dirty money for the criminals.
Also, you might say "Just deactivate the stolen keys", but for small devs or companies they don't have the resources and there would be too much public outcry.[2]
[1] G2A charges a fee with G2A shield which is buyer protection (similar to ebay's protection) but they charge a fee for it, or they won't replace a broken key.
[2] This happened when EA killed a couple thousand keys of Battlefront 2 that were purchased by illegal credit cards and faced a fuck-ton of rage.
You can buy keys with BTC and then sell them to refill your wallet or find a seller via the forums.
Sorry for the mini rant.
~Zapo