You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Fun story: OkCupid deleted my account after a period of activity, and when I contacted support, they said they didn't send me a warning email because I had unsubscribed from all email communication! Now all the earliest messages between my SO and I are gone.
I'm not sure what the moral is here. Maybe "Don't let users unsubscribe from emails regarding their data being deleted or their card being charged."
