Re: @Steven Roper
Why did he plead guilty? Simply because he was guilty.
As was pointed out by AC above, the very act of unzipping an archive file means you are guilty of making an indecent image. Further, if you then view the files you've just unzipped, you end up creating a new image in your PC's graphics memory, which again means you are guilty of creating an indecent image.
The whole possessing and creating laws were originally to do with physical items, such as photographs, where there is a clear physical distinction between possessing a photo that someone else made, and going out and taking your own photos. The extension to digital media makes little sense, but does have the "bonus" effect of making the act of possession sound as bad as the act of creation of original material.