"I don't think there's any doubt now that the NSA or other agencies monitor or record almost every telephone call made in the United States, including cellphones, and I presume email as well," Carter told The Associated Press in an interview. "We've gone a long way down the road of violating Americans basic civil rights, as far as privacy is concerned."
If intelligence services were monitoring Carter, they might gain insights into various hotspots and crises. Carter and his wife Rosalynn have visited more than 140 nations. The former president runs The Carter Center, which has pursued human rights, humanitarian work and offered political mediation and election monitoring since he left office in 1981.
Carter negotiated a nuclear disarmament pact with North Korea in 1994, which subsequently unraveled, and went to Pyongyang again in 2010 to secure the release of a U.S. citizen who had been detained. He visited Syrian President Bashar Assad in 2008, and has been to Cuba, Vietnam and many other countries of interest to U.S. intelligence. Carter Center monitors have observed disputed elections in Venezuela and many other nations.
Carter is also one of the "Elders," a group formed by Nelson Mandela in 2007 that includes senior and retired leaders who work together on peace-building and humanitarian initiatives. They include former Irish president Mary Robinson, South African Archbishop Desmond Tutu, former U.N. secretary-general Kofi Annan, and former Finnish president Martti Ahtisaari.
Carter said the surveillance state is now so omniscient that he has turned to "snail mail" in an effort to avoid snooping.
"For the last two or three years, when I want to write a highly personal letter to a foreign leader, or even some American leaders, I hand-write it and mail it, because I feel that my telephone calls and my email are being monitored, and there are some things I just don't want anybody to know except me and my wife."
It's a twist on the state of affairs that Carter left when he departed the presidency in 1981.
"When I was in office I was deeply concerned by the intrusion of the security agencies, the intelligence agencies, on American privacy," he said.
Carter promoted the establishment of FISA courts under the Foreign Intelligence Security Act, requiring U.S. intelligence agencies to get a federal judge to approve any monitoring of a U.S. citizen.
"When I left office, they couldn't do that with even one American person" without the court's approval, he said.
But the public and Congressional demand for increased intelligence-gathering after the Sept. 11, 2001 terror attacks that killed nearly 3,000 Americans swept away those safeguards.
"After 9/11 took place, under President George W. Bush and later under President Obama, the FISA Act has been drastically modified," Carter said. It is now a "mainly a rubber stamp" for unlimited snooping, approved by member of Congress, most of them without knowing any details unless they are on one of the Intelligence committees.