Even if you have location tracking turned off on your smartphone it would appear that Facebook can still work out where you are.
The news comes in information that Facebook has supplied to Senators Christopher A Coons and Josh Hawley, you can see exactly what Facebook is doing below.
Even if someone does not enable location services, Facebook may still understand information about the location based on information that they and others provide through their activities and connections on our services. For example, if someone responds to an event on Facebook for a local music festival, upload a location-tagged video, or gets tagged by a friend in a check-in at a restaurant, these actions have give us information about that person’s likely location. Similarly, a person might share where they live by setting a location in Marketplace or adding their address to their profile.
Facebook is apparently also using people’s IP address to track their locations, surely they should not be able to do this if you have told them already that you do not want their location tracked.
The company keeps coming under criticism for the way it uses peoples data, this should come as not surprise that they are tracking out location even when they have been told not to.
Source The Hill, 9 to 5 Mac