The Office of the Director of National Intelligence sent a memo late last week to contractors warning them about the Washington Post’s article on the growth of top-secret agencies and contracting activity.

The undated, unsigned memo, which was leaked to numerous media outlets, including The Daily Caller, framed the Post piece as a national security threat.

“Foreign intelligence services, terrorist organizations and criminal elements will have potential interest in this kind of information. It is important that companies review their overall counterintelligence posture to ensure that it is appropriate,” read the memo, which was addressed simply from the ODNI’s Mission Support Center (read the full memo here).

“Specifically, we recommend that companies affected by this publication and website assess and take steps to mitigate risk to their workforce, facility and mission, to the extent consistent with your contractual relationship with ODNI. These steps should include re-enforcement of security and counterintelligence protections and steps to enhance workforce awareness,” it said.

The element of the Post project that likely prompted ODNI’s concerns is the searchable database in which readers can find all companies that do intelligence-related work for the government. However, the database is limited. It does not include exact company locations or addresses. Similarly, a map of the country that shows locations where intelligence work is performed does not include precise, Google Earth-type detail.

A more detailed memo from Art House, the head of ODNI’s communications, was obtained late last week by the Atlantic’s Marc Ambinder. House told agency officials that “the Post advises that ‘links’ between individual contractors and specific agencies have been deleted, although the Post will still cite contractors and their locations.”

However, the Post database does not lay out where companies are located beyond a city or town. In some cases, there is a discrepancy between where a company is listed as being located and where its own website says its offices are.

For example, HBGary Federal is a 25-employee company established in 2005. It is listed as being located in Columbia, Md. But its website says it is in Bethesda, Md. It could be a clue that the company does work for the National Security Agency, which is located in Columbia. In fact, an HBGary spokesperson contacted The Daily Caller and said the company was previously located in Columbia but is now in Bethesda, as is indicated on their website.

In the article itself, a handful of intelligence-related sites are identified in such a way that they would be easy to find simply by reading the article, though someone who was looking for them would have been able to find them anyway. Again, however, the precise location of the buildings are not given.

In an Arlington County office building, the lobby directory doesn’t include the Air Force’s mysteriously named XOIWS unit, but there’s a big “Welcome!” sign in the hallway greeting visitors who know to step off the elevator on the third floor. In Elkridge, Md., a clandestine program hides in a tall concrete structure fitted with false windows to look like a normal office building. In Arnold, Mo., the location is across the street from a Target and a Home Depot. In St. Petersburg, Fla., it’s in a modest brick bungalow in a run-down business park.

Here is another portion of the article that identifies building locations:

To get another view of how sprawling Top Secret America has become, just head west on the toll road toward Dulles International Airport.

As a Michaels craft store and a Books-A-Million give way to the military intelligence giants Northrop Grumman and Lockheed Martin, find the off-ramp and turn left. Those two shimmering-blue five-story ice cubes belong to the National Geospatial-Intelligence Agency, which analyzes images and mapping data of the Earth’s geography. A small sign obscured by a boxwood hedge says so.

Across the street, in the chocolate-brown blocks, is Carahsoft, an intelligence agency contractor specializing in mapping, speech analysis and data harvesting. Nearby is the government’s Underground Facility Analysis Center. It identifies overseas underground command centers associated with weapons of mass destruction and terrorist groups, and advises the military on how to destroy them.

The story will undoubtedly spur debate over whether too much information was disclosed. But given the scope and size of the intelligence-related spending and infrastructure that the article reveals, it appears that the counter-argument — that there needs to be more transparency and oversight of this secret world — will carry weight.

E-mail Jon Ward and follow him on Twitter

WATCH: INTELLIGENCE FAILURES 5.21.10