It took two years and the help of over a dozen journalists to complete, but The Washington Post has finally published the first of a series of investigative reports into the sprawling build-up of national security agencies and contractors in the wake of 9/11. "After nine years of unprecedented spending and growth, the result is that the system put in place to keep the United States safe is so massive that its effectiveness is impossible to determine," write Dana Priest and William H. Arkin. (Watch a promo for "Top Secret America.") Here are just a few of the key numbers unearthed by the newspaper's team of reporters:

Approximately 854,000 people, "nearly 1.5 times as many people as live in Washington D.C." have top-secret security clearances. 

Buildings housing top-secret intelligence workers completed or under construction since 9/11 occupy 17 million square feet of space in Washington and surrounding areas, "the equivalent of almost three Pentagons."

"At least" 263 government organizations have been created or reorganized as a response to 9/11. In total, 1,271 government agencies work on counterterrorist, homeland security and intelligence programs in the U.S.

Around 1,931 private contractors work with government organizations on homeland security and counterterrorist programs — 484 companies alone work with the National Security Agency. Even the Coast Guard outsources work to as many as 44 private contractors.

Every day, the National Security Agency intercepts and stores 1.7 billion e-mails, phone calls and "other types of communications." It is able to sort a "fraction" of these into 70 separate databases.

Read the "Top Secret America" investigation in The Washington Post.