Happened to come across this option in the Global Settings for Adobe Flash when I was viewing a video looking for a quality control since my internet connection at home is a meager 768kbps.
Right-click on the flash video and choose Global Options then Advanced. Scroll to the bottom and you’ll see this:
From Adobe (source):
Protected content
Some content on the Internet (such as movies and music) requires that users
first get content licenses from the content provider before playing the content.
These content licenses are automatically downloaded to your computer, for
example, when you rent or purchase protected content. Flash Player saves these
licenses on your computer. Deleting the license files prevents Flash Player from
playing this protected audio or video content, even if the content itself
remains on your computer. This is called deauthorizing your computer. If you
decide to sell, donate, or dispose of your computer, deauthorize it to prevent
unauthorized users from playing protected content later.
Be careful when resetting license files. When you reset license files, Flash
Player resets all existing license files for protected content that plays on
your computer in Flash Player. You cannot access this content from this computer
until you have downloaded new licenses from your content provider.
