Galaxy
I would just say no. The last thing I want is people knowing where I am. Couldnt think of anything worse. Fine as long as everyone agrees as long as no coercion. And I suppose as long as people dont act hurt when people say no.
When you say that you don't want people knowing where you are, I understand that.
I have nothing to hide, I don't visit venues or locations that are in any way 'shady' or dubious - I just want to feel free to spontaneously do something or go somewhere if I feel like it without another person thinking it's 'out of character', or to question why I took one route instead of another. It feels controlling. I don't want a family member or anyone else to speculate, 'well-she-went-there-yesterday-why-is-she-going-there-again-today'...
My late ex's mother was also controlling. She'd call me on occasions when I was out, and the next time we met up, she'd say, "I called you on Tuesday afternoon but you weren't there in an accusatory tone. Dread to even think what she would've said if she'd been able to track me! 
I do though understand those who need to keep tabs on vulnerable youngsters or family members going on long trips, or into isolated locations. But that's completely different.