The work that DARPA does is incredible and we should be proud, as a country, that we pursue transformational research. One of the big weaknesses of the private sector is that there are few opportunities to pursue high-risk high-reward research and research that must be done on long timelines.

The stuff DARPA funds is fundamentally important and has an incredible track record.

That said, their primary customer is the DoD which has demands for technology that is sometimes rather creepy. Without going too far down that route and forcing a tangent on the thread I'll just plug here that technology is power and that power can be used for good and evil, for noble and ignoble and for personal or public gain. We need to cheer on DARPA for its development of technology and keep its customers accountable for how it applies that technology.