Your location is being tracked and recorded via your mobile device. Many private companies are recording and selling this info. Many drone assassinations in the Middle East are targeted via the location of a persons mobile device.

Turn off location (GPS)

Unless you are actively using an app that requires location such as your navigation software, switch off location. Make a shortcut in your devices settings to make it easy to switch this off.

Turn off location permissions for your Apps

There are many Apps that are sending your location back to their servers with most reserving the right to sell that data. Review all Apps that have permission to view your location and unless it directly needs to use location, disable it.
If your mobile device does not allow you to disable specific permissions, install another App that will allow you to control permissions.

Your location can be triangulated via mobile towers

Turning GPS location off removes the location data for most services and private trackers. The authorities can still locate you as your mobile device communicates to numerous mobile towers to connect to the phone system. By working out the location and your distance from the towers, they can triangulate your location.
Switch to aeroplane mode or switch off your phone.

Secure location

If the privacy of your location is very important, do not not trust your mobile device and do not bring it with you. You may consider asking a friend to baby-sit your mobile device to send out dummy location data.

Photography and meta-data

Meta-data in files such as photographs can contain location data. So if you took photos of your children and posted them to social media, it may be possible for a random person to download the photos, extract the location meta-data and know where your children live.

To illustrate this concept, the website I know where your cat lives searches online for cat photos and locates them on a map.
Check all your Apps that take photo and video and switch off location data.