For all the talk in Washington about border security, the one agency charged with providing it isn't sharing a wealth of details. So a group of volunteers -- called Secure Border Intelligence -- has stepped in, working around the clock in Arizona to keep a thorough record of the front lines of the border battle.

Using tiny, motion-activated cameras hidden in the desert along known smuggling routes, the group captures images of illegal immigrants streaming into the U.S. Some carry water, others bundles of drugs slung across their shoulders. SBI also records conversations between Border Patrol pilots and agents on the ground. Excerpts from those conversations, obtained exclusively by Fox News, suggest the border may not be as secure as frequently portrayed by the Obama administration.

The following is one exchange recorded by the group:

Drone Operator: "We haven't been in that area for hours... we're being inundated where we're at."

Fixed-wing Pilot: "This is Night Owl on air four. You guys got targets out there?"

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Drone Operator: "Are you kidding me? We just broke the record."

Helicopter Pilot: "We're going to need another person over here, we've got about 50 bodies out there."

Fixed-wing Pilot: "What's your plan on the group of 20 or so that's outstanding?"

Drone Operator: "Working a group of 37."

Helicopter Pilot: "Left side of the bird, left side of the bird ... bodies and bundles."

Each day, the group posts an audio track taken from the previous 24 hours. The conversations are intercepted off un-encrypted U.S. Border Patrol channels -- it's not unlike people who listen to police and fire department scanners. After listening to agents' back and forth, much of it laced with GPS coordinates, mile markers and known landmarks, the group compresses a 24-hour day into a 10-minute compressed audio file.

On Tuesday, the group noted agents caught three Chinese illegal immigrants. The next day, agents identified 223 immigrants either in or trying to enter Arizona illegally, according to Wednesday's audio download.

The material is distributed as part of an effort by SBI to '"document the porous US/Mexico border (and) to expose the 'lie' by fostered the current administration that our borders are secure," one of the founders told Fox News. "This documentation is being offered to you and any other news organization without any copyright, distribution, or other restrictions with the stipulation that credit be given."

Customs and Border Protection insists the administration is cranking up border security efforts.

"Under this administration, DHS has dedicated historic levels of personnel, technology, and resources to the Southwest border," the agency said in a recent statement to Fox News. "CBP has more than doubled the size of the U.S. Border Patrol since 2004. In FY 2012, CBP employed over 21,300 Border Patrol agents, keeping staffing levels along the border at an all-time high. Additionally, CBP continues to deploy proven, effective surveillance technology tailored to the operational requirements along the highest trafficked areas of the Southwest Border."

The SBI group also uses trail cameras to document the flow of illegal immigrants. Because the video cameras are motion-activated, batteries last for weeks. The latest pictures were downloaded and provided to Fox News on Sunday. They show groups of illegal immigrants nonchalantly walking through the desert on their way to Phoenix and Tucson, and pick-up points in between. The cameras appear to have been placed at a position that is a one-to-four days walk north of the border.

However, it's possible not everyone on the video actually escapes the Border Patrol, since the agency uses a layered approach to security. Agents do not always interdict illegal immigrants at the border -- sometimes apprehensions take place five to 10 miles north after several shifts. So it is impossible to know whether all immigrants captured by SBI camera's successfully escaped the Border Patrol.

Asked more about their membership and means, the group's founder said they preferred to remain anonymous for fear of being targeted.

"Due to the sensitive nature of our endeavor, further disclosure of the mechanism of our efforts cannot be disclosed," he said. "We would prefer that the story be about the 'smoking gun' information provided rather than about the 'messenger' providing the information."