THis has probably been discussed before but i couldn't find it that quick. All digital cameras, including those on smartphones, store something called EXIF data in the photo. It stores lots of things like shutter/aperture, ISO setting, what lens/focal length you used, whether flash was used (the exact features depend on your camera). But beware if you have a digital camera or smartphone with a GPS reciever! Now this is often a useful thing as well, as you get maps when you are travelling - but the camera software often also stores the location of your photo in the EXIF data.
Worst case scenario is that you have a huge farm and a nice marijuana growing operation going on. It will be easy for authorities to locate your grow area from just one picture. If you live in a city it's less of a problem because GPS is accurate within 10 to 50 feet.
Some websites like facebook wipe it automatically when you upload pictures. I'm going to look in to the possibilities to delete the exif data automatically as well.
How to delete exif data?
-Switch off geotagging
-Remove the exif data with software (i always use easy exif delete)
-Make print screen of the picture
-Or use a camera without GPS receiver....
Any other ideas?