Card sharing has established itself as popular method of pirate decryption.

Card sharing is a particular concern to conditional access providers, and their respective pay-TV companies, as well as the DVB consortium.

An arguably legitimate use for card sharing is the sharing of the control word within a home network, where the subscriber is authorised by the subscription television network to decrypt their signal, using one smart card.

Card sharing utilises the integral scrambling system of the DVB standard, DVB-CSA, meaning that every provider of scrambled DVB content has potential to be affected by it.