Doing a little googling, it looks like Palantir is a somewhat suspicious cyber-spying company implicated in a number of dragnet espionage programs. For instance

Doing a little googling, it looks like Palantir is a somewhat suspicious cyber-spying company implicated in a number of dragnet espionage programs. For instance, China's espionage program used, in part, for political oppression in Tibet. It also looks like he distanced himself from an effort to use his software to try to take down Wikileaks. I'm not entirely sure what sorts of things Palantir really does and if I'd consider them ethical or anti-privacy, but it does seem like a point of concern and probably what the person above you was referencing.