I realize this is a technology forum, so it's popular to think about it in a very laser-focused kind of way where technology is neutral, and it's only the WAY that people use it is a problem, but over and over in society we have seen that this is simply not true.
Nuclear fission is politically and ethically neutral. An atomic bomb isn't.
A hunting rifle is politically and ethically neutral. A fully automatic assault rifle isn't.
A search engine is politically and ethically neutral. The way that Palantir packages and presents it and the use cases it optimizes for isn't.
Now, I realize that there are a million different grey areas and exceptions with all these subjects. You can murder people with a chef's knife, after all. I'm certainly not out here claiming that if something CAN be misused it should be banned.
I'm not even necessarily saying that something shouldn't be built OPTIMIZED for a particular use that some would consider unethical. There is always the very excellent argument that technology can't be repressed, and if you don't build "the thing", someone else will. You can't put the genie back in the bottle.
But we all know that there are lines that are too far. I don't want to jump straight to Godwin's Law, but I would say we as society universally agree that it was indefensible for corporations to provide tools and technology to facilitate the holocaust and any form of genocide.
I am not saying that ICE or certain US police forces are comparable to Nazi Germany's organizations. But there is a spectrum. And somewhere on that spectrum there is a line. And the line needs to be incorporated and considered from a humanistic point of view - one of global ethics. (vs. national ethics such as "If the US does it it's not illegal/unethical").
And from that standpoint, myself, and many others, think Palantir's ethics and chosen way of business is way over where we draw the line.