Ask HN: Have you seen your Palantir file?

Data brokers and government records.

No, you can't except under limited circumstances. In America, data about you is largely confidential property of others that can be resold without your knowledge or consent. It likely includes errors and erroneous assumptions, but there's little or no recourse because of decades of legislative, legal, and regulatory capture because of bribes given and patronage bought by the ultra rich who still aren't satisfied with the lion's share of everything.

Depending on what you saw, Lexis-Nexis was very detailed and until the late 1990s, was not well audited - which meant that things like PTRAK did not have much governance to its use.