american allies. reports that drew sharp criticism from top members of congress in both parties. >> the reports are very disturbing. friends don't spy on friends. >> reporter: or do we? is spying on friends still going on? >> is the united states now listening in on the phone conversations of friendly presidents and prime ministers? >> john, i'm not going to get in to discussions of specific activities, intelligence gathering activities. >> we are listening in to the conversations of friendly heads of state. >> again i'm not going to talk about specific or alleged or reported intelligence gathering operations. >> reporter: the head of the nsa warned that new limits on u.s. espionage could be dangerous. >> is much more important for this country that we defend this nation and take the beatings than to give up on a program that would result in this nation being attacked. >> reporter: the u.s. has been under fire over reports the u.s. collected tens of millions of