Facebook can determine where users are even if they opt out of having their whereabouts tracked, the company revealed in a letter sent to US senators.
Responding to a request for information by two senators, the world's largest social network explained ways it can still figure out where people are after they have selected not to share precise location data with the company.
The company contended that knowing a user's whereabouts has benefits ranging from showing ads for nearby shops to fighting hackers and battling misinformation.
Facebook said it is figuring out a user's location by looking for users that have been tagged in a photo at a specific place or check-ins at locations. People may share also an address for purchases at a shopping section at Facebook, or simply include it in their profile information.
In addition, devices connecting to the internet are given IP addresses and a user's whereabouts can then be noted.
Facebook said knowing a user's general location helps it and other internet firms protect accounts by detecting when suspicious login behavior occurs.
Facebook said recently that it is ready for a data privacy law that is to go into effect in its home state of California at the start of next year.
The California Consumer Privacy Act (CCPA) will give internet users the right to see what data big tech companies collect and with whom it is shared.