If you're interested in reading more about how your location will be tweeted, check out Twitter's Support forum and note the following:
When using Tweet With Your Location, please keep in mind:
- Your exact location will be stored with your Tweets, and your exact location or place information may be publicly displayed based on your application settings.
- Once you post your location, it’s public. Even if you delete it later, it can remain in third-party applications or other external sources, like search results.
- Turning off the Tweet With Your Location feature will opt-out your account from future location sharing, but doesn't remove historical data. You can remove all your location data from your Tweets in your account settings (the How to Tweet With Your Location help page has instructions to do this).