A centralized intelligence database on all Americans is not inherently legal.
It likely breaks the Privacy Act of 1974, the Foreign Intelligence Surveillance Act (FISA), the 1st, 4th and 5th Amendments.
This must be stopped. Contact your Senators and Representative and ask them to stop it. I use @5calls to call mine.
https://newrepublic.com/post/195904/trump-palantir-data-americans