Sorry, but Conditional Access systems get compromised, all the time. ITV Digital went tits up largely because it could not stem the leak of customers when its CA system could be bypassed with a microcontroller and eeprom - hell the market for pirate stuff was so large that the hack was manufactured en masse in smart-card form factor. Likewise Sky and Virgin Media. The whack-a-mole game was very expensive for the providers, and even when they thought they had made their smart cards secure enough the pirates discovered how to share the decryption keys from one legit card across the 'net.
CA will spell the end for the BBC as an independent body because they will be forced to throw in with the most secure (for the moment) CA provider (which pretends to be independent from Murdoch these days) or if they choose a rival system they will quickly go the same way as Canal+, Multivision, Premiere, Stream TV and the many, many others on the long list of providers whose systems were 'compromised' and were eventually assimilated by the Murdoch empire anyway (which is maybe what this is about all along...)