It has become increasingly clear now why the United States government is so anxious to crack down on whistle-blowers, pursuing over 20 charges against Bradley Manning, a US soldier who gave secret government and military documents to WikiLeaks, hunting down former National Security Agency contractor Edward Snowden who revealed the NSA's vast surveillance programs around the world, and even trying to arrest Julian Assange, the WikiLeaks' editor-in-chief and founder who published secret files.

On Wednesday, Glenn Greenwald, one of the first journalists to report Snowden's revelations in May in the British newspaper The Guardian, again shocked the world by reporting another US secret surveillance program revealed by Snowden.

The so-called XKeyscore program is touted by NSA in its training materials as its "widest-reaching" system for developing intelligence from the Internet. It allows analysts to search with no prior authorization through vast databases containing e-mails, online chats and the browsing histories of millions of individuals. This new revelation showed how easy it is for the administration to access databases, which US President Barack Obama and House Intelligence Committee Chairman Mike Rogers have blatantly denied.

An analyst just has to fill out a simple on-screen form giving a broad justification for the search. The requests are not reviewed by a court or any NSA personnel before they are processed.

The new revelation means that if Snowden, reportedly issued Russian entry document on Thursday, is sent back to the US, he will face more charges than Manning, whose sentencing hearing began on Wednesday.

Also on Wednesday, senior US intelligence officials testified before the Senate Judiciary Committee on the surveillance programs and released classified documents regarding the massive gathering of phone records, as revealed by Snowden.