Operation Underground Railroad (O.U.R.), an organization dedicated to ending child slavery and sex trafficking around the world, is using dogs trained in electronic-storage detection (E.S.D.) to put pedophiles behind bars domestically.

O.U.R. trains and equips local law enforcement to investigate, arrest, and prosecute people who violate children. This year, O.U.R. has provided 10 canines trained in E.S.D. to local law enforcement to “sniff hard drives where criminals are storing their horrible material that prosecutors gather,” said Jerry Gowen, executive director of O.U.R.

In a recent interview with The New Yorker, an E.S.D dog handler named John Hyla, of the Putnam County Sheriff’s Office in New York, explained how a canine’s nose can track down hidden flash drives, cell phones, hard drives, and micro S.D. cards.

“If there’s a McDonald’s cheeseburger on a plate, you and I would just smell a cheeseburger. A dog smells the bun, the burger, the cheese, the sesame seeds, the lettuce. The smell of a memory device is equivalent to the smell of the lettuce—the faintest of all the scents,” Hyla said.

The dogs are trained to smell triphenylphosphine oxide, a compound used to protect the memory chips in all electronic-storage devices. The most common cyber criminal the dogs are used to find are sex offenders.

Canines are not the only species fighting sex crimes with O.U.R. In addition to teaching and equipping local law enforcement, O.U.R. agents often work sting operations, posing as buyers to bring down people who traffic children. Since their founding five years ago, O.U.R. has rescued 3,100 victims out of slavery and assisted in the arrests of more than 1,700 traffickers across 24 countries and 25 states.

“If we’re able to help law enforcement put criminals behind bars, then we are saving children,” Gowen said.

This Giving Tuesday, O.U.R.‘s goal is to raise $50,000 to go toward their mission of eradicating child sex trafficking. Donors who give $39 or more will receive a book curating the art and poetry of sex trafficking survivors from around the world.