Tyler Fingert:

Some people have even returned stolen wood, and it ends up here, often referred to as the conscience pile.

Back in Saguaro National Park, to help make sure theft doesn't happen, the National Park Service has turned to technology, putting tiny passive trackers in some of their cacti, allowing them to identify ones stolen from the park. Of their roughly 1.9 million saguaro cacti, only 1,000 of them are tagged, the ones close to roads and the smaller cacti, those most likely to be stolen.

The trackers, which are similar to pet microchips, don't actively broadcast a signal, so if a cactus goes missing, Ray O'Neil, Saguaro National Park's chief ranger, says the only way to know if it's from the park is to scan it using a reader, making the trackers more symbol than substance.