There are circumstances to be met to ban your Steam Account:
1. Some unfair Steam users buy game gifts and game items using carding techniques (stolen or scammed cards), then sell it to other users or make trades on lowered prices. When credit card holder restores his card, he is cancelling all transactions, that was made when his CC was in possession. Steam pulls back all items, which were bought using that card - so all users, who bought anything from that unfair person, losing all - games and money from inventory or library. Also, Steam Tech Support will apply ban to ALL accounts, who bought those games - even user had not any idea about that those games comes from illegal way.
Official reason of Account ban Applying: 'Use of stolen/scammed credit cards and alternate account to transfer games to their main account'.
