Would this not be a great way to infect thousands of
network operations systems due to a PDF exploit? It
is like "free beer" to many network operators, they
just *have* to consume it. One could take control
of the "network" by taking control of the systems
of the people operating it and silently watch
for the passwords, names, ip addresses that will
enable one to take control later.
I know, I am just being paranoid. There has never
been an exploitable PDF exploit. Oh, wait, there
has been 
One has to admit it would be one hell of a
combined social engineering and technical
exploit if it could be pulled off.
Gary