And inspiring america, an exnfl pro changing lives. Nightly news begins right now. From nbc news World Headquarters in new york, this is nbc nightly news with lester holt. Good evening to our viewers in the west. The cia is urgently assessing the impact of what may be one of the most damaging exposures of vital secrets the agency has ever experienced. Purported details released by wikileaks of how the cia is able to turn personal and home devices into potent eavesdropping tools for spying overseas. In short, the keys to the agencys cyber arsenal. Tonight nbc news has learned a scramble is on within the cia to find the source of the leak, possibly one of their own. We get details from nbcs andrea mitchell. Reporter tonight the cia and fbi racing to find out who is behind what could be one of the worst u. S. Intelligence breaches in modern history. That bombshell release of thousands of documents wikileaks claims were stolen from the cia. Nbc news now learning from a senior u. S. Officia