people after checking out the original ntl digital cards it seems to have a nargrvasion logo on the back of it. does it mean that it is encrypted using nagravision and that it is possible to hack , im very curious with this one people.
Although I'm somewhat dubious about their ability to do this, it is technically possible that using digital technology, they can create a return path via the unused frequencies of the telephone line (as in ADSL) this would enable the box to phone home. It would certainly make the use and accounting for of PPV events much more simple.
It is a simple matter for the cable engineer to hook up a spectrum analyser to the green box at the end of the road, and look at the signals emanating from the box on the line going to your house/flat etc.
Owing to the construction of the STB internals (plastic and copper) all manner of frequencies from the switched mode power supply, demodulator circuit, MPEG chipset and most importantly the final RF circuit will find their way back onto the cable run.
All the engineer has to do is silently sweep the UHF spectrum from ch 21-69 and take a look at what clear TV channel is being viewed. This can be logged and times recorded ready for the ensuing bill/summons to be dropped through the door.
Fitting a high quality return path UHF isolator goes some way to helping but once again the telephone line will contain most info to secure a conviction unless the chipping is very well organised.