Now playing
04:01
His part-time job is Russian troll hunter
Now playing
04:04
Meet the people who helped prevent WW III
Now playing
03:45
Meet the mom who went undercover as a terrorist
Mario Tama/Getty Images North America/Getty Images
NEW YORK - OCTOBER 15, 2001: (SEPTEMBER 11 RETROSPECTIVE) A corporate mailroom employee uses gloves while sifting through letters October 15, 2001 in New York City. Recent reports of anthrax in the mail have caused procedural changes in mailrooms throughout the country. (Photo by Mario Tama/Getty Images)
Now playing
01:07
Are we at risk for an anthrax attack?
Now playing
01:48
The world's fastest plane
crack99 takedown declassified ron_00000101.jpg
Now playing
01:34
Watch feds arrest a Chinese cyber pirate
FBI
Now playing
01:27
Another Cuban mole in the US government
FBI
Now playing
01:25
How the U.S. busted a Cuban spy
CNN
Declassified Ep. 4 Montes 2_00011710.jpg
Now playing
01:18
Cryptic code in purse exposes Cuban spy
Declassified Ep. 2 Saddam 1_00002816.jpg
Now playing
01:25
The search for Saddam Hussein
Declassified Ep. 2 Saddam 2_00001913.jpg
Now playing
01:12
The manhunt for Saddam Hussein
north korea history spying assassinations pkg hancocks _00001209.jpg
Now playing
02:15
North Korea's history of covert operations
erin simon area 51 is real_00010325.jpg
Now playing
02:11
Area 51 is real, but sorry, no aliens
myers apartment search declassified ron _00012020.jpg
Now playing
01:28
What US spy hunters found in a traitor's home
nicholson declassified father son spies _00001815.jpg
Now playing
01:38
Phone calls make CIA traitor's son a suspect
Bill Hennessy/CNN
Walter Kendall Myers, 72, and his wife, Gwendolyn Myers, 71, are charged with conspiracy to act as illegal agents of the Cuban government, providing classified information to that government and wire fraud, according to court documents.
Now playing
01:02
Cuban spy Kendall Myers had a surprising partner
hijacked egypt air passenger declassified ron_00010807.jpg
Now playing
01:34
Hijacking victim: 'I realized it's not a drill'
PARDI/ASSOCIATED PRESS
One of the three hijackers of EgyptAir flight 648 appears at the open doorway at Luqa airport in Valletta, Malta, Nov. 24, 1985. The jet bound for Athens was diverted to Malta on Nov. 23 by the Abu Nidal Group. (AP Photo/Pardi)
Now playing
01:25
'I will kill a passenger every 15 minutes'
CNN/1985
Now playing
01:27
Shots fired on a plane at 35,000 feet
CNN
Declassified Ep. 6 Angry Talon 1_00011203.jpg
Now playing
01:20
Ex-Taliban officer helped free American hostages
CNN
Declassified Ep. 6 Angry Talon 2_00002901.jpg
Now playing
01:03
Film about Jesus lands aid workers in a Taliban prison
CNN
Declassified Ep. 7 Chi Mak 2 _00003404.jpg
Now playing
01:19
Dumpster diving for evidence of a spy
CNN
Declassified Ep. 7 Chi Mak 2 _00001419.jpg
Now playing
01:16
Searching a spy's home without leaving a trace
Declassified Ep. 1 Trigon/Moscow 1_00002328.jpg
Now playing
01:24
Recruiting a Soviet to spy for America
Declassified Ep.1 Trigon/Moscow 2 _00003021.jpg
Now playing
01:31
An American female spy goes undercover in Moscow
CNN
Declassified Ep. 8 Hexagon 1_00003103.jpg
Now playing
00:48
The Cold War version of Google Earth
CNN
Declassified Ep. 8 Hexagon 2_00005724.jpg
Now playing
01:08
Spying on the Soviets from space
CNN
Declassified Ep. 5 Cross International_00010612.jpg
Now playing
01:32
The fake company that busted an Iranian arms dealer
CNN
Declassified Ep. 5 Cross International 2_00003012.jpg
Now playing