Yes it is, as long as the person’s human rights are considered, ie their right to respect for their home and their private life.
In those circumstances – ie some sensitivity as to what the tech monitors and assuming it leaves some parts of the person’s life private – as per expectations of common decency – it is likely to be perfectly legal.
That is because the Care Act makes getting anything for one’s needs a matter of a professional judgment as to there being a deficit or a difficulty that is creating significant impact, and putting that in plain English, it means that a council can ask an applicant for public money to co-operate in establishing the evidence basis for the problem, before it finds the person eligible in that regard, and offers a solution.
A person in receipt of public money is not able simply to assert that there has been no change in needs; any council can ask to be satisfied, and it is likely that tech is going to become more central in informing those evaluations on which a care package depends. A person’s needs do not HAVE to have changed, before a package can be revised, in principle, because all councils have to cope with providers going out of business or throwing their contracts back these days, and thus the people drawing on services need to face that reality as well.
If a council were to say it’s their way or the highway, ie it was a condition of a decision on eligibility that one puts up with this, then it might be possible to use public law and judicial review to challenge the appropriateness of such a stiff stance. But sensible correspondence about reasonable adjustments should prevent that situation arising.