They work with law enforcement agencies and help them process data they legally collect into other government databases. Their main product is merging data from various databases and adding a UI layer for analysis.
Basically, Palantir is a data integration company that works for government and larges businesses under contract. Some data they get hired to work on includes surveillance data and military intelligence collection.
It's on prem at the customer.
In a healthcare context, internal pricing and patient data are heavily protected by law. If Palantir were as guilty of surveilling your medical data as you allege, that would be tremendously illegal, and companies much larger and more influential would have strong legal grounds to sue it into oblivion. If you think Palantir has a tight grip on the government, consider the influence of the health systems it works with—some of which are the largest employers in their states. The idea that an all-powerful company can control the government doesn’t make sense if smaller companies, which donate less, are somehow exerting unchecked control over larger ones.
Of course, most of these concerns stem from two things: (1) its approach to autonomous warfare and (2) concerns about immigration surveillance. Autonomous warfare is coming, whether you like it or not. Palantir’s role in that is not related to its work in the commercial sector—unless you're suggesting they’re holding back potential revenue by not selling highly advanced robotics to corporate clients. Concerns about immigration surveillance are also somewhat overstated because, again, Palantir legally cannot use data from its commercial work (unless one of its clients severely mismanaged their contract). In that case, it’s really the U.S. government you should be criticizing — not the contractor simply trying to make money.