RWarehall: Those games were probably bought as gifts with a stolen credit card. They are not in his account. The thief has likely sold the keys on G2A or some other shady site. And the unlucky buyer will likely have the games removed as soon as the real credit cardholder revokes the purchase.
cogadh: Possibly, but most of the account hijackings that have been seen so far are just people trying to gain access to games already in an account, not to use it as a front for fraudulent gift purchases. There are entire sites out there where you can buy compromised GOG, Steam, Origin, pretty much any game service's accounts and have been for years. The purpose of these sites is not to provide and "end run" around things like GOG's gifting restrictions, which are relatively recent. It is far more likely that this is yet another account bought from a sketchy Russian forum solely for the purpose of obtaining an already populated library.
Except that the OP specifically states that whoever got access to his account spent bought $75 worth of games. There's pretty much no reason someone would log into a stranger's account to spend their own money on games which would then be tied to the aforementioned stranger's account; therefore the intruder was either very, very, very stupid, or he was using stolen card data to buy gift codes to sell or trade elsewhere.
