Palantir started as a data intelligence firm focusing on predictive analysis, shopping its wares to the government. They have gotten really, really, really amazing at predictive data and are now moving into the private sector, selling predictive analysis tools to healthcare, insurance, security, etc for all kinds of applications.

Palantir has technologies that see everything, scrape everything, and store everything. They are not public with all of their products or capabilities, and their choice of bedfellows doesn't inspire confidence that they are altruistic with regards to who they do business with. From what I've heard by way of one-off comments and drunken bragging from people who work/have worked their, their capabilities are far beyond even the remotest of media speculation.

Palantir lives the realities of its customers: the NSA, the FBI and the CIA–an early investor through its In-Q-Tel venture fund–along with an alphabet soup of other U.S. counterterrorism and military agencies. In the last five years, Palantir has become the go-to company for mining massive data sets for intelligence and law enforcement applications, with a slick software interface and coders who parachute into clients’ headquarters to customize its programs. Palantir turns messy swamps of information into intuitively visualized maps, histograms and link charts. Give its so-called “forward-deployed engineers” a few days to crawl, tag and integrate every scrap of a customer’s data, and Palantir can elucidate problems as disparate as terrorism, disaster response and human trafficking.

Palantir’s advisors include Condoleezza Rice and former CIA director George Tenet, who says in an interview that “I wish we had a tool of its power” before 9/11. General David Petraeus, the most recent former CIA chief, describes Palantir to FORBES as “a better mousetrap when a better mousetrap was needed” and calls Karp “sheer brilliant.”

Among those using Palantir to connect the dots are the Marines, who have deployed its tools in Afghanistan for forensic analysis of roadside bombs and predicting insurgent attacks. The software helped locate Mexican drug cartel members who murdered an American customs agent and tracked down hackers who installed spyware on the computer of the Dalai Lama. In the book The Finish, detailing the killing of Osama bin Laden, author Mark Bowden writes that Palantir’s software “actually deserves the popular designation Killer App.” [1]
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Clients include the Los Angeles Police Department which used Palantir to parse and connect 160 data sets: Everyone from detectives to transit cops to homeland security officials uses Palantir at the LAPD. According to the document, Palantir provides a timeline of events and has helped the massive police department sort its records.

As of 2013, Palantir was used by at least 12 groups within the US Government including the CIA, DHS, NSA, FBI, the CDC, the Marine Corps, the Air Force, Special Operations Command, West Point, the Joint IED-defeat organization and Allies, the Recovery Accountability and Transparency Board and the National Center for Missing and Exploited Children. The Centers for Medicaid and Medicare Services were planning on pilot testing the use of Palantir in 2013 to investigate tips received through a hotline. A second test was run by the same organization to identify potentially fraudulent medical providers in the Southern region of the US.

The U.S. spy agencies also employed Palantir to connect databases across departments. Before this, most of the databases used by the CIA and FBI were siloed, forcing users to search each database individually. Now everything is linked together using Palantir. In fact, cyber analysts working for the now-defunct Information Warfare Monitor used the system to mine data on the China-based cyber groups GhostNet and The Shadow Network.[2]

[1]http://www.forbes.com/sites/andygreenberg/2013/08/14/agent-o...
[2]http://techcrunch.com/2015/01/11/leaked-palantir-doc-reveals...