There’s no doubt that the Global Positioning System – or GPS – ranks as one of the most influential technologies during the 20th century. It’s revolutionised warfare and spawned whole new industries from the development of Homer Simpson-voiced in-car satnav systems to real-world treasure hunting games likes Geocaching. Being able to accurately identify your location and navigate routes without paper maps, compass or an intimate knowledge of constellations is a breakthrough now widely taken for granted.
But as with any technology, the availability of accurate positioning information can come with some downsides.
What’s the risk?
Geotagging and geolocation are two widely used terms to describe activities involving the sharing and identification of location information.
Smartphones and digital cameras often come equipped with the capability to embed GPS coordinates – normally in EXIF format – in every photo they take. Geotagging, for example, allows you to include geographical information in the metadata that accompanies a photo or video shared online.
This EXIF data can be used to build a collaborative visualisation of popular locations but can also be used to identify where someone goes, works or lives.
If your devices are logging and sharing location information, it’s possible you may leave geolocation information online as part of your digital footprint. EXIF can store latitude and longitude, bearing, altitude and speed information alongside what camera, aperture and other settings you used.
If you publish a lot of photos or videos online then there’s a chance that details of your daily routine could be identified. Parents are often keen to ensure that children taking and sharing selfies and posting pictures online don’t reveal where they live or go to school and location information could be just as revealing as a unique school uniform design.
How to check what you’re sharing for geolocation information
If you’re security conscious or keen to protect your online privacy then check if your devices are storing GPS data in the EXIF format. You may decide you don’t want to share this information online.
Modern digital cameras may have GPS logging built in so check the device settings or the user manual.
Smartphone owners can also easily check if their devices are tagging photos or video with coordinates:
- On iPhone, check Settings -> Privacy -> Location Services to see what and when you share location info.
- On Android, settings change according to the software version or manufacturer so you may need to dig around in the general settings or camera settings or look for a guide to your particular device online.
Here are some common ways to check photos to see what details are captured and stored:
- If you use the Firefox or Chrome browser, search for and download the Exif viewer extension
- If you’d rather use a website then try out the www.pic2map.com service
- Windows computer users can find a photo, right click on it and select ‘Properties’. On the Details tab, latitude and longitude coordinates should be listed under ‘GPS’.
- Mac users can right click on a photo and select ‘Get Info’. You can then review the latitude and longitude coordinates – if any – under ‘More Info’.
Many social media sites and apps now take a conservative approach to location data stored within photos or videos uploaded to their platforms:
- Facebook strips out metadata by default when you share an image online so if your photo is saved by another person it will not include location information. Do note though that you may be asked to tag a location during the upload process.
- Review what apps you use to share photos and video and check with the site provider what they do with location information.
- The Embedded Metadata Manifesto site has assessed what EXIF information is kept and stored by various online services.