  VAPR. It sounds like a nefarious spy agency bent on world
domination, doesn't it?  Instead, VAPR stands for Vanishing
Programmable Resources, and it's a new program created by DARPA
-- the Defense Advanced Research Projects Agency -- to develop
tech that self-destructs either on demand or at a pre-scheduled
time. That's not to say it isn't involved in the world of
espionage. That's exactly its point. According to DARPA:
Sophisticated electronics can be made at low cost and are
increasingly pervasive throughout the battlefield. Large numbers
can be widely proliferated and used for applications such as
distributed remote sensing and communications. However, it is
nearly impossible to track and recover every device resulting in
unintended accumulation in the environment and potential
unauthorized use and compromise of intellectual property and
technological advantage.  That's all another way of saying: "We
want to send spy toys over enemy lines that we might not be able
to get back, so we want to blow them up