Hypothetical situation:
You take a picture using your only digital camera. You download it, think it valuable for your non-anonymous blog or facebook account, and upload it as it is, for other people to see, knowing it was you who took it. For whoever it is viewable, it is possible to right-click on it and find, among other things:

• Image Type
• Width
• Height
• Camera Brand
• Camera Model

You then take a picture using the same digital camera, you download it to your computer, and then you upload it, as it is, to your anonymous blog or to an open-publishing site that allows for anonymous publishing.

Then some one else downloads your picture. They right-click on it and the view their properties. They see:

• Image Type: SAME AS BEFORE
• Width: SAME AS BEFORE
• Height: SAME AS BEFORE
• Camera Brand: SAME AS BEFORE
• Camera Model: SAME AS BEFORE

Even if you do not do this, it is a matter of privacy to keep your camera model and the date you took your picture out of the public realm. And publishing the brand of your camera is in a way giving them some kind of free publicity.

To delete this information before publishing your pictures, I use The GIMP. I always “Save As” another name, to keep the original on my computer for reference. On the dialogue box that appears, I click on “Advanced Options”, untick “Save EXIF data”, then save with the new name.