>> reporter: intelligence officials revealed more about how the systems work. the program aimed at telephone records gathers logs of phone numbers dialled by u.s. phone customers and dumps them into an enormous database maintained by the nsa. but director of national intelligence james clapper says the government is prohibited from indiscriminately sifting through it. in other words officials say no data mining. >> nobody is listening to your telephone calls. >> reporter: the data is checked he says only when there is a specific phone number or pattern of calls associated with foreign terrorists. >> the only way to do that is if you have all the records in one place at that time. if you're looking for a needle in a haystack you need a haystack. >> reporter: the latest highly secret program to be revealed allows the nsa to plug into servers run by the biggest internet companies to monitor suspected terror communications. clapper says it is intended to