Ten Democratic lawmakers are seeking more information about how the tech company Palantir is helping the Trump administration build what the lawmakers described as a “government-wide, searchable, mega-database” that connects sensitive tax and other government data. In a letter to Palantir CEO Alex Karp, the lawmakers described the database as a “surveillance nightmare” that “will make it significantly easier for Donald Trump’s Administration to spy on and target his growing list of enemies and other Americans.”