If hefty fines aren't enough to stop people from littering in Thailand's national parks, officials hope that good, old-fashioned guilt-tripping will do the trick. As The New York Times reports, Khao Yai National Park in central Thailand responded to a recent littering offense by mailing abandoned trash back to the litterbugs who left it there.

The responsible party left behind a tent filled with trash after camping overnight in Khao Yai. In Thailand, littering in a national park is punishable by up to five years in prison and a $16,000 fine. The park officials took a less conventional approach to this particular crime. After cross-referencing equipment rental forms with a discarded prescription bottle, they were able to track down the offenders and mail them their forgotten garbage.

The clear bag of trash came with a note. “You have forgotten some of your belongings at the Khao Yai National Park,” it read. “Please let us return these to you.” Varawut Silpa-archa, Thailand's environment minister, referenced the incident in a Facebook post, writing, “I will pick up every single piece of your trash, pack them well in a box, and mail it to your home as a souvenir." In addition to getting a package of trash in the mail, the unidentified campers have also been banned from staying in the park overnight.

Officials tasked with protecting the environment have seen firsthand the damage litter can cause. Plastics can take centuries to break down, and in that time they pose a serious threat to wildlife. Trash that builds up in places where people seek refuge can also be bad for their mental health. A 2015 study found that seeing litter on a beach counters the restorative qualities of being in nature.

[h/t The New York Times]