The "sole" purpose (again, their website shows a ton of other use cases) appears to be to assist elected governments in violating somebody's rights/privacy. From where I sit, elected governments decide what's "socially useful".

For better or for worse, the American electorate approves of the CIA/FBI -> https://news.gallup.com/poll/224804/republicans-push-governm.... This is even more the case for defense, which is just about the only American institution that has had a reliably consistent approval rating -> https://truthout.org/articles/why-does-the-us-military-have-...

Alex Karp's CEO letter makes a similar point: "The engineering elite of Silicon Valley may know more than most about building software. But they do not know more about how society should be organized or what justice requires."