“It was a revelation—especially given the public outcry over Snowden’s leaks—that agencies could just buy some of the data they needed straight from commercial entities. One technology consultant who works on projects for the US government explained it this way to me: ‘The advertising technology ecosystem is the largest information-gathering enterprise ever conceived by man. And it wasn’t built by the government.'” Byron Tau in Wired: How the Pentagon Learned to Use Targeted Ads to Find Its Targets—and Vladimir Putin.