The duplication of copy-protected data by analog means.
The analog hole (aka, the analog loophole) is a crucial threat to any attempt at content and copy protection. By leveraging the analog hole, any Digital Rights Management (DRM) protection can be removed.
Even if data is kept completely secure up to the point where it appears on a screen and played on a sound device, from that point onward it can always be re-captured using a video camera or microphone.
It is a perceived fundamental and inevitable vulnerability in copy protection schemes and security protection.