[anigbrowl]

Yes, but who does that in real life outside the tiny community of extreme hardware nerds? Absolutely such things are possible, but they're increasingly impractical. It's the same reason that people promote widespread adoption of encryption; there's no encryption so strong that it couldn't be easily circumvented at the endpoints by really dedicated sppoks, but the sheer inconvenience is itself a safeguard against mass surveillance.

[jsprogrammer]

Only one person has to do it.

Beauty of digital.

As for the spooks, depends on what you mean by "easily".

Edit: According to a video[1] posted on Vimeo (which claims to be from a DMCA hearing) representatives of the MPAA appear to make recommendations on how to do the capture and they provide some tips that will increase the quality of the final product.

For example, hooking directly into the audio output; and, removing other light sources.

[1] http://vimeo.com/4520463