>>> been an open secret that the u.s. government has a sophisticated electronic spying capability. the more we learn about the targets the more heat is directed at obama administration. today the heat was coming from home and abroad. in washington, hundreds from both ends of the political spectrum took to the streets to demand the nsa reign in survey surveillance of americans. while in europe there were revelations the u.s. was listening in on phone calls of close allies. it appears to be the kind of public response edward snowden was hoping for when he began spilling secrets earlier this year. mi michael isikoff reports.

>> reporter: hundreds marched on capitol hill today protesting nsa surveillance and cheering a fresh message from their hero in moscow, fugitive ex-nsa contractor edward snowden . are you grateful he's done what he did?

>> we wouldn't have the reforms for the nsa if not for what he did.

>> reporter: the rally comes amid more fallout overseas from snowden disclosures. d erk der sp irgsigel today reported angela merkel was targeted since 2002 when she was still an opposition leader . this after president obama was forced to apologize to merkel over disclosures of snooping and a pledge to investigate reports the nsa hacked into his computer. one world leader did rally to the nsa's defense. british prime minister david cameron .

>> what snowden is doing and what the newspapers are doing in helping him do what he's doing is frankly signalling to people who mean to do us harm how to evade and avoid intelligence.

>> reporter: intelligence officials are bracing for more snowden disclosures.

>> in the aftermath of the disclosures from snowden we did a review of the potential damage. i don't think we have certainty about everything he has.

>> reporter: despite months of intensive forensic work officials have yet to get a full accounting of the tens of thousands of documents snowdenning took with him.