The problem may be a bit more serious, depending where the real bug is. If rovio/someone forgot to enable some security mechanisms it is all right. But if the only security available atm in ovi store is the process of buying, it is a disaster for developers. Who will stop me (except for my consciouses) from sending this premium .deb package to all interested? Even after I actually buy this? It is not even piracy, so simple it is.