I'll start with the typical lawyer response. I think it depends.
I can envision a couple of scenarios drawn out of your particular example. I can envision a scenario where, let's say in Ontario, OHIP or the provincial Ministry of Health has reason to believe that an individual has been outside the province or outside the country for an entire year and thus shouldn't qualify for health insurance. There is some evidence to that effect, so as part of its more routine anti-fraud investigations, it looks to find different data points it can collect. One can argue that in those instances it is necessary.
A different situation, though, might well be that there are claims that one way to reduce health care spending at a provincial level is to try to weed out those who aren't eligible who are claiming so that we need to be actively monitoring everybody's movements to try to proactively identify who doesn't qualify and thus remove them from the insurance rolls. That doesn't strike me as a particularly wise thing to do and wouldn't meet the kind of standard that we might want to establish.