Comment by jasonfarnon

"Yes, Google might collect location data even when you’re not using Maps (there are a lot of passionate, dedicated Timeline users), but you have to have that enabled"

Of course that opt-in requirement was only the result of a hard-fought class action settlement.

Take this with a grain of salt as my recollection of the litigation is somewhat hazy. But I believe Google argued, even when a user opted out of location tracking, Google could still keep the data for its own uses. Ie opting out of location tracking simply meant the user didn't have access to their location history, it didn't show up on the phone (couldn't be searched by suspicious spouses) etc.