In the missive, which was widely shared on social media Tuesday, Facebook explained ways it can still figure out where people are after they have selected not to share precise location data with the company.
The social network, which was responding to a request for information by two senators, contended that knowing a user's whereabouts has benefits ranging from showing ads for nearby shops to fighting hackers and battling misinformation.
"There is no opting out. No control over your personal information," Republican Senator Josh Hawley said in a tweet.
"That's Big Tech. And that's why Congress needs to take action."
Facebook said that clues for figuring out a user's location include being tagged in a photo at a specific place or a check-in at a location such as at a restaurant during a dinner with friends.