Is it obligatory for someone who has become accustomed to purchasing pirated computer programs and games without the permission of the producing companies to buy original copies of them in order to repent, or is it sufficient for him to stop and seek forgiveness, knowing that the liability falls upon those who copied and sold them?

Purchasing pirated software, for which the owners have not given permission to copy, is impermissible because it falls under aiding in sin. Aiding in sin is prohibited, as Allah Almighty says: "And do not cooperate in sin and aggression. And fear Allah; indeed, Allah is severe in penalty." Whoever repents from this and resolves not to return to it is not obligated to purchase the original copies.