Then you commit a crime. Not by retaining the copy but by making it. You generally cannot commit a crime by passivity though such as by not doing something. So simply retaining a copy you legally acquired cannot be illegal. As a comparison, if you rent a car, but never return it, then that's not a crime. It's generally called theft by conversion but it's a civil matter, not a criminal one. In IA's case though, they were the one making that copy. That you could commit the same crime another way doesn't really absolve theirs.