Jesus, I'm absolutely horrified at the number of people who are OK with tracking!!
I would not be OK with another adult tracking me (I'm open about where I'm going, who I'm with and am completely able to find a way to get in touch with all my nearest and dearest if I'm running late/need a lift/stuck in traffic). Why would my mum or her partner need to know where I am - or me know where they are? It's 30 years since I left home, they can go wherever they want.
As for my kids. I (up until now) thought I was a bit helicopter-y in my parenting. They've had phones since before they started secondary school. But when they were younger, if they were going out it was usually to a friend's house, and I'd have ok'd it with their parent. Now they're older they are again open with me about where they're going, and with who, and when they'll be home. They know my mobile number and have been able to repeat it since maybe 8 years old. They call or message me if their plans change. We live in the suburbs of a city, and I've travelled to 'town' with them so many times I'm not worried about them getting lost, or finding the right bus. Since they were tiny they've been taught to 'find a shop lady' if they got separated from me - I have every confidence they can figure minor problems out by themselves, and delight in telling me how resilient they were afterwards.
Why on earth do folk think its OK to have such access to others' lives as this? And why do they think they need it? The chances of serious incident (I mean things like child abduction, murder on the way home from the pub, rather than tea being delayed by 10 minutes) are so, so minute that this seems completely dis-proportional.