How Team of Geeks Cracked Spy Trade

In 2003, Mr. Thiel pitched an idea to Mr. Karp: Could they build software that would uncover terror networks using the approach PayPal had devised to fight Russian cybercriminals?

In the past two years, Palantir’s work in Washington has expanded from eight pilot programs to more than 50 projects, executives say. The Australian government is now a client, and the NSA is eyeing Palantir, as is the U.K., current and former government officials say.