There are two really two major concerning issues with Palantir:

1. They provide tech that is used to select targets for drone strikes and apparently also for targeting violent attacks on US civilians. I don't know too much about how the algorithm works but simply outsourcing decisions about who lives or dies to opaque algorithms is creepy. It also allows the people behind the operations to avoid personal responsibility for mistakes by blaming the mistakes on the software. It also could enable people to just not think about it and thus avoid the moral question entirely. It's an abstract concern but it is a legitimate one, IMO.

2. I don't know if this is 100% confirmed but we have heard reports that Elon Musk and DOGE collected every piece of government data that they could get their hands, across various government departments and databases. These databases were previously islands that served one specific purpose and didn't necessarily connect to all the other government databases from other departments. It's suspected that palantir software (perhaps along with Grok) is being used to link all of these databases together and cross reference data that was previously not available for law enforcement or immigration purposes. This could enable a lot of potential abuse and probably isn't being subjected to any kind of court or congressional oversight.

They sell data derived from the data. But it's not, like, a hash function - you can absolutely deduce the source data from it. In fact, that's the entire purpose. You use the aggregation and whatnot bullshit to find individuals, track them, gain insight into their living situation and patterns, and acquire evidence of crimes. Typically that requires a search warrant.

If you couldn't go backwards Palantir wouldn't have a market. So, I would consider that a loophole.