The only thing US surveillance needs to read the contents of your email, with no prior authorization whatsoever, is your email address.
The only thing US surveillance needs to read your private Facebook chat or private messages is your user name and a date range.
In fact, according to newly revealed documents given to The Guardian by Edward Snowden, one program, called XKeyscore, enables the National Security Agency (NSA) to see “nearly everything a user does on the internet”.
The NSA's training materials boast about XKeyscore being its "widest-reaching" system for squeezing intelligence from the internet, The Guardian reported on Wednesday.
On that same day, senior US intelligence officials testified to the Senate judiciary committee amidst the raging debate over mass surveillance.
The Guardian once again turned to documents revealed by whistleblower Edward Snowden to detail XKeyscore.
Those documents depict how XKeyscore allows NSA analysts to search, with no prior authorization, through vast databases of emails, online chats and browsing histories of millions of individuals.
Read more: http://nakedsecurity.sophos.com/2013/08/01/newly-exposed-nsa-tool-xkeyscore-sees-nearly-everything-we-do-online/