https://en.m.wikipedia.org/wiki/Palantir_Technologies#Contro...
Also:
> When intruders from the hacker group Anonymous gained access to thousands of emails stored on the servers of the security firm HB Gary Federal, the emails revealed that Palantir had worked with HB Gary Federal to develop proposals for attacking WikiLeaks’ infrastructure, blackmailing its supporters and identifying donors.
http://www.forbes.com/sites/andygreenberg/2011/02/09/did-sec...
There was also the sex scandal with their founder and a Stanford student: http://www.nytimes.com/2015/02/15/magazine/the-stanford-unde...
This thread on HN also has some discussion about their government and military contracts: