well, from what I heard the more popular a place is the more public it becomes to the point that it could be come 'totally public' if it reaches a threshold (no mention what they are, though).
And as they were clear to state all the way through - this is about creating persistent stories that are permanently attached to a place page on FB - so presumably your home's place page becomes public.
That concerns me about having private parties in private homes (pretty typical use case)
Perhaps the becoming 'totally public' of a place is contingent on the non-intersection of the sociality of some x number of checkins. I.e., if you have a party at you place but everyone who checks in is within 1-2 degrees of your social graph, then Facebook recognizes it's a well known place within a very local user subset. And doesn't make it public.
Also — time could be a simple indicator. If a place (i.e., your house) suddenly has 100 checkins over one day only to have no serious checkin traffic again for weeks, then that wouldn't be a completely public location either.
"That concerns me about having private parties in private homes (pretty typical use case)"
I'd be interested in finding out how they calculated popularity in this case. How many parties and how well-attended would they have to be in order to automatically make a home a public place?
And as they were clear to state all the way through - this is about creating persistent stories that are permanently attached to a place page on FB - so presumably your home's place page becomes public.
That concerns me about having private parties in private homes (pretty typical use case)