Who else might be watching? Britain's spies collected millions of images from video chats, according to the latest secrets spilled by NSA leaker Edward Snowden. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP

Glenn Greenwald, left, and David Miranda after Miranda's arrival at Rio de Janeiro's International Airport on Aug. 19, 2013. Miranda had been detained for nine hours at London's Heathrow Airport. Authorities questioned him about Greenwald's reporting of the "NSA leaks." Ricardo Moraes /Reuters/Landov hide caption

itoggle caption Ricardo Moraes /Reuters/Landov

Travelers at Pearson International Airport in Toronto earlier this month. At an unnamed airport, Canada's spy agency tested a program that allowed them to track those who took advantage of free Wi-Fi. Aaron Harris /Reuters/Landov hide caption

itoggle caption Aaron Harris /Reuters/Landov

Surveillance camera video of Aaron Alexis, a contractor who killed 12 people at the Washington Navy Yard on Sept. 16, 2013. Alexis was one of thousands of individuals cleared by the firm known as USIS. HO/UPI/Landov hide caption

itoggle caption HO/UPI/Landov