You have a phone, people know where you are
Its really that simple. Google and Facebook are using information that's inherent to the operation of all mobile devices. So -- if you think the Feds are getting your location from them, that's second hand data, its easier to just get it from the service provider.
You can't turn it off because unfortunately that's how the equipment works. Your equipment might like to give you the illusion of privacy because its easier to do this than try to explain to people what's going on and why.