I've got my hands, temporarily, on a Canon EOS-1D.
I rattled a few frames through it. I can see them on the (tiny) LCD screen when pressing Display and scroll through them by pressing Select and twiddling the wheel.
However when I plug the camera into my Ubuntu machine via USB or put the SD card directly into it there are no images. I can't even see a date related folder.
I've yet to try it on a windows machine and suspect it may be a formatting issue or some proprietary protection of some sort. Meanwhile, any clues?