The inevitable next step is coming, there's now a formal proposal in the works to start installing cameras in houses in the UK
Hardly a "formal proposal".
As the article you linked to says:
"It needs to be stressed that this is just the idea of one academic - Professor Neil McKeganey of the centre for Drug Misuse Research at Glasgow University"
I don't know how things operate in the US, but in the UK no one takes outlandish suggestions by a university professor very seriously. 3 years ago the same prof said that female drug addicts should be paid to take long term contraception. That idea sank without trace too, even though it was far less controversial and far more sensible. He's also suggested the children of drug addicts should be removed from their parents and taken in to local authority care, and no one paid any attention to that, either.