EXIF metadata is easy to automate. What if there is a logo of a local business reflected on a surface that most people barely notice.
Someone recognizes this, tracks the person down.
It's a bit over the top, but these things happen. If that exposes one of those underage girls, who is accountable?
Leaking real world information can be done in many and subtle ways. There are times where people think the image origin is untraceable, but it isn't. Will reddit take the heat? The poster? The mod?