You can screengrab at the interface between the decoder in the monitor and the panel itself, using an LVDS capture card. Not cheap at the moment, and you still have to process the gigabits per second of uncompressed video, but you can expect the Chinese to come up with some inventive and low-cost solutions if they start locking down the other routes... in fact a lot of DRM-stripping hardware already exists for sale, if you know where and what to look for.
With a bit more dedication and electro knowledge, I'm sure one could open up a screen and capture the data straight from the output circuit. Few people can do this, but piracy doesn't need more than one source to be distributed over the world.
