Virgin Media has announced new encryption technology will be installed across Edinburgh and the rest of Scotlands former Telewest DTV network to prevent unauthorised set-top boxes from accessing the service.

The media giant has refused to release how many city homes are currently kitted out with hoo dodgy STBs, but one cable installer suggests it could run into the tens of thousands.

“There is only one cable network in the city, installed years ago by Telewest as it was then, with EEC grants. That’s how Virgin Media and I would estimate there are possibly hundreds of thousands of homes in Edinburgh using Virgin. Of these, I would say over 50 per cent are ‘illegitimate’ in large areas of the city, sourced from Sunday markets or online, so its a huge problem,” said Rick Bond, of Bond Electronics, a specialist TV installer and servicer.

According to Mr Bond, dodgy STBs cost around £99 up-front, but that’s cheaper than the legitimate monthly subscription of between £20 and £50 depending on what channels you want to subscribe to.

Updated TV smart cards are apparently being sent out to all Virgin Media subscribers to try and disrupt unauthorised viewing of subscription channels. Customers will need to replace the existing cards inserted in the set-top box.

However well executed by Virgin Media, it seems even legitimate subscribers could be affected. If the card fails to be replaced, then many of the previously viewable channels will be blocked over the coming weeks until it will not be possible to watch TV at all.

Virgin Media claims to have the UK’s most advanced TV on demand service and, with ten million customers in Britain, it is the second largest provider of pay TV in the UK. But according to Bond Electronics, its Scottish encryption technology has been less sophisticated than its competitors in the satellite and broadband market. That may change this month in Scotland at least.