I'm using Acrobat XI and an unsecured PDF document. I used the selection tool to highlight the image I wanted and tried both ctrl+c and copy from the edit menu. The program pops up the message that it's being copied to the clipboard, but when I go to paste it somewhere I get nothing or 'The clipboard doesn't contain an image'. I can copy and paste other things just fine; for example I can print screen and then paste that.
Perhaps related, I can't cut the selection from the PDF either. It's greyed out.
Documents properties shows it was created in Acrobat Distiller 10.1.4