You are careful with what you post on social networks, right? Think again.
YouTube prankster JackValeFilms was able to get a lot of information about the user in question based off of geotags set in public Twitter and Instagram posts. The conversations he had may look like he is psychic - but should be eye opening.
How Do You Prevent This?
For users of Instagram, the best way to avoid a situation like this is to set your posts to private. To do this, go into your profile settings and set your photos to PRIVATE. This way, the only people who have access to your feed are those you allow to see your posts. (See the illustration below.)
If you would like your photos to be public, you can make sure your posts aren't added to your Photo Map or are Geo-tagged with GPS data. Before you share a photo, ensure the "Add to Photo Map" option is turned off.
What About Twitter?
Make certain your posts aren't set to publish your location. Ensure that you turned off the location marker by both not enabling scheduled tweets, or by making sure the location services icon is turned off before tweeting.
These tips can help, but the best tip to avoid your personal information making it's rounds around the Internet is to make sure you enable and consitently check your privacy settings, and being vigilant of what you share and to whom.