What is the ruling on money earned from selling gaming accounts that require entering credit card data (most likely stolen) to activate the account, then removing it after activation, knowing that the card is not used for payment but only for account activation?

It is not permissible to use credit card numbers that a person does not own, and whose owners have not authorized their use. The sale of these accounts depends on the website's terms, and it appears that the website stipulates that each account must have a credit card belonging to its owner. Therefore, it is not permissible to sell them because they are not rightfully owned.

Thus, the money acquired from selling these accounts is not permissible to benefit from. You must either reclaim the accounts from those you sold them to and return their money, or if that is not possible, then donate the money to the poor and needy, while refraining from this prohibited act.

If recording these numbers causes harm to their owners, then you must bear that harm. If you do not know their owners or the harm caused to them, then seek Allah's forgiveness, regret your action, and stop doing it in the future. For the paths to lawful earning are many, and "whoever fears Allah - He will make for him a way out and will provide for him from where he does not expect."