To be fair, while the channel rights enforcement is done "client side," the real work is likely done by an M-Card in your set-top box. This is a secure environment that contains hardware to support decrypting MPEG streams on the fly. The M-Card is able to decrypt key bundles that are sent out-of-band and in-band in the video streams.
The bar to get channels you're not subscribed to is quite a bit higher because of this mechanism, alas.
The bar to get channels you're not subscribed to is quite a bit higher because of this mechanism, alas.