It is not hard to edit the metadata. I think the current reference point for picking out forgeries is a RAW file - not that they are impossible to manipulate ei

It is not hard to edit the metadata. I think the current reference point for picking out forgeries is a RAW file - not that they are impossible to manipulate either but it is harder, plus the kind of statistical analyses done in the article would be more meaningful on an image that is supposedly completely unedited.