I fail to see how being able to do it without a warrant could help legitimate police work.
A phone’s current location (or last known location) is another matter, as I can imagine emergency situations where a warrant would take too long to get, but the location history? Nope. No way.
Edit: OK, maybe a short excerpt of the most recent locations can be useful to locate a fugitive or an endangered person, but there needs to be a strict limit.
