(Patrick Semansky/AP)

Barton Gellman, the Washington Post reporter who broke the news of the NSA online content collection program PRISM, says the government asked him to suppress the names of the nine companies participating in the program.

Speaking at a Cato Institute conference on Wednesday, Gellman said The Washington Post has a practice of talking to the government before running stories that may impact national security. According to Gellman, there were "certain things" in the PRISM slides that they agreed raised legitimate security concerns. But, he said:

The thing that the government most wanted us to remove was the names of the nine companies. The argument, roughly speaking, was that we will lose cooperation from companies if you expose them in this way. And my reply was "that's why we are including them." Not in order to cause a certain result, or to get you to lose your cooperation but if the harm that you are describing consists of reputational or business damage to a company because the public doesn't like what it's doing or you're doing, that's the accountability we are supposed to be promoting.

Gellman believes that it's because the names were released that many of those technology companies started to be vocal advocates of greater transparency about the program. While they "previously had very little incentive to fight for disclosure because it wasn't their information that was being collected and there was no market pressure," he said, these companies "are now, because they are suffering business damage and reputational harm, pushing very hard in public debate and in lawsuits to disclose more about how the collection program works," which current FISA Court orders prohibit them from telling the public about.

Spencer Ackerman, a Guardian reporter who has worked closely with Glenn Greenwald on NSA stories, was on the same panel. He agreed that the "market question is really a tremendous one" when it comes to responses to the Snowden revelations. A report earlier this year estimated that the NSA leaks could cost $35 billion over the next three years.