janine claytd phyllis greenberger, we thank you. >> thank you. >> ifill: later tonight on most p.b.s. stations, frontline airs the second part of "united states of secrets." tonight's installment focuses on the relationship between u.s. technology giants and the national security agency. the following portion reveals some of the tech community's reaction to revelations that the n.s.a. was accessing data from major internet players like facebook, yahoo, google and skype. the agency called the program, prism. >> narrator: on the other side of the country, in silicon valley, there was anger and confusion over just what kind of access major internet companies were giving the nsa. >> there was shock and disbelief and horror. a lot of people i know, silicon valley-type people, just felt, "it can't be right. it's not possible google, facebook, these guys are collaborating. it's not just what they would do." >> the ceos of internet companies like facebook and google denied... >> narrator: the companies scrambled to respond to the news. >> google denies that they have direct access. who's righ