After three years of cleanups, the federal government has achieved no better than a 1 percent solution for the problem of trash left in Southern Arizona by illegal border-crossers. Cleanup crews from various agencies, volunteer groups and the Tohono O'odham Nation hauled about 250,000 pounds of trash from thousands of acres of federal, state and private land across Southern Arizona in 2002 to 2005, says the U.S. Bureau of Land Management. But that's only a fraction of the nearly 25 million pounds of trash thought to be out there.

Crossers burying border in garbage By Tony Davis, Arizona Daily Star

The interesting thing is that some open borders nuts are blaming not the illegals, but the federal government for fighting back:

Other activists from Derechos Humanos, Defenders of Wildlife and No More Deaths say the trash piles show what happens when the feds deliberately drive the entrants into the desert, by sealing the borders in cities. "If you were going to cities, you wouldn't need to carry three days' worth of food," said Kat Rodriguez, a coordinator-organizer for Derechos.

This is another reason why a fence would pay for itself.