Where were you last Tuesday at 2:35pm? Not sure? Well, your iPhone can tell you. Your android can, too, actually.
Your iPhone has been tracking your every move, and likely transmitting that date back to Apple and you probably had no idea. Androids share tracking info with Google directly. Companies claim to use this information to create "personalized service" (like ad targeting, how kind of them), but who knows what it's really used for? It could be shared with law inforcement, advertisers, and if your employer provides your phone, well, they can have access, too.
Every place you've visited, every minute you've spent there, it's all being stored and shared. Feels a little violating, doesn't it? Imagine that anyone with access to your android account can look at that information online, and anyone with access to your phone can see your every move? (I imagine there are many spouses wondering about the usefulness of that right about now. . .)
Go to Settings
Scroll down and select Privacy
Select Location Services, then System Services at the very bottom
Select Frequent Locations (and marvel at all the places you've been over the last month), then turn off