I think 5 years is fair
I think 5 years is a fair sentence assuming they have been selling hundreds or thousands of these boxes. They took the risk, they failed or got greedy and now they pay. Nice to see a sentence given out that might make others think twice before filling the new gap in the market.
It might even reduce the amount of smug gits on benefits on council estates bragging about how they get free cable and how they got their gas cooker fitted for free by claiming they could smell gas and all the other scams they learn about down the pub while the rest of the world is out working.