AMD and ATI's new graphics technology will block you.
The details are here. The lowdown is short: the newest graphics technology will block you from accessing the frame buffer -- a memory area on the graphics card that stores images and video. This is being done to prevent you from copying videos if you're unauthorized (99.99% of the users will be unauthorized).
Here's a quote from the article:
Video, audio, and software will all drive a similar road, that being a single, unmodifiable path from the original encoded, licensed source to rendering, and on to delivery (display, headphones, portable device, printer, or memory for execution of software). This bit of progress seems to have little relevance to IT until you expand the meaning of the word “content” to encompass that which you create that is consumed by human eyes and ears.